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                                                                    EXHIBIT 10.4

                          FORM OF SUBSIDIARIES GUARANTY


                  SUBSIDIARIES GUARANTY, dated as of September 24, 1999 (as
amended, modified or supplemented from time to time, this "Guaranty"), made by
each of the undersigned guarantors (each a "Guarantor," and together with any
other entity that becomes a guarantor hereunder pursuant to Section 26 hereof,
the "Guarantors"). Except as otherwise defined herein, capitalized terms used
herein and defined in the Credit Agreement (as defined below) shall be used
herein as therein defined.


                              W I T N E S S E T H :


                  WHEREAS, Information Holdings, Inc. ("Holdings"), Warburg,
Pincus Information Ventures, Inc. ("WPIV" and together with Holdings, the
"Parent Guarantors"), Information Ventures L.L.C. (the "Borrower"), the lenders
from time to time party thereto (the "Lenders"), Bank of America, N.A., as
Documentation Agent, and Bankers Trust Company, as Administrative Agent
(together with any successor agent, the "Administrative Agent"), have entered
into a Credit Agreement, dated as of September 24, 1999, providing for the
making of Loans to, and the issuance of Letters of Credit for the account of,
the Borrower as contemplated therein (as amended, modified as supplemented from
time to time, the "Credit Agreement") (the Lenders, the Collateral Agent, the
Documentation Agent and the Administrative Agent are herein called the "Lender
Creditors");

                  WHEREAS, the Borrower may at any time and from time to time
enter into one or more Interest Rate Protection Agreements or Other Hedging
Agreements with one or more Lenders or any affiliate thereof, and provided that
such Interest Rate Protection Agreement or Other Hedging Agreement constitutes a
Guaranteed Obligation of the Borrower, (each such Lender or affiliate, even if
the respective Lender subsequently ceases to be a Lender under the Credit
Agreement for any reason, together with such Lender's or affiliate's successors
and assigns, if any, collectively, the "Other Creditors," and together with the
Lender Creditors, the "Secured Creditors");

                  WHEREAS, each Guarantor is a direct or indirect Subsidiary of
the Borrower;

                  WHEREAS, it is a condition to the making of Loans to, and the
issuance of Letters of Credit for the account of, the Borrower under the Credit
Agreement that each Guarantor shall have executed and delivered this Guaranty;
and

                  WHEREAS, each Guarantor will obtain benefits from the
incurrence of Loans to, and the issuance of Letters of Credit for the account
of, the Borrower under the Credit Agreement and the entering into by the
Borrower of Interest Rate Protection Agreements or Other Hedging Agreements and,
accordingly, desires to execute this Guaranty in order to satisfy the conditions
described in the preceding paragraph;

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                  NOW, THEREFORE, in consideration of the foregoing and other
benefits accruing to each Guarantor, the receipt and sufficiency of which are
hereby acknowledged, each Guarantor hereby makes the following representations
and warranties to the Secured Creditors and hereby covenants and agrees with
each Secured Creditor as follows:

                  1. Each Guarantor, jointly and severally, irrevocably,
absolutely and unconditionally guarantees: (i) to the Lender Creditors the full
and prompt payment when due (whether at the stated maturity, by acceleration or
otherwise) of (x) the principal of and interest on the Notes issued by, and the
Loans made to, the Borrower under the Credit Agreement, and all reimbursement
obligations and Unpaid Drawings with respect to Letters of Credit issued under
the Credit Agreement and (y) all other obligations (including obligations which,
but for the automatic stay under Section 362(a) of the Bankruptcy Code, would
become due), liabilities and indebtedness owing by the Borrower to the Lender
Creditors under the Credit Agreement or any other Credit Document to which the
Borrower is a party (including, without limitation, indemnities, Fees and
interest thereon), whether now existing or hereafter incurred under, arising out
of or in connection with the Credit Agreement or any such other Credit Document
and the due performance and compliance by the Borrower with all of the terms,
conditions and agreements contained in the Credit Agreement and such other
Credit Documents (all such principal, interest, liabilities, indebtedness and
obligations being herein collectively called the "Credit Document Obligations");
and (ii) to each Other Creditor the full and prompt payment when due (whether at
the stated maturity, by acceleration or otherwise) of all obligations (including
obligations which, but for the automatic stay under Section 362(a) of the
Bankruptcy Code, would become due), liabilities and indebtedness owing by the
Borrower under any Interest Rate Protection Agreement or Other Hedging
Agreement, but only if such Interest Rate Protection Agreement or Other Hedging
Agreement constitutes a Guaranteed Obligation of the Borrower, whether now in
existence or hereafter arising, and the due performance and compliance by the
Borrower with all of the terms, conditions and agreements contained in the
Interest Rate Protection Agreements or Other Hedging Agreements, but only if
such Interest Rate Protection Agreement or Other Hedging Agreement constitutes a
Guaranteed Obligation of the Borrower, (all such obligations, liabilities and
indebtedness being herein collectively called the "Other Obligations," and
together with the Credit Document Obligations, the "Guaranteed Obligations").
Each Guarantor understands, agrees and confirms that the Secured Creditors may
enforce this Guaranty up to the full amount of the Guaranteed Obligations
against such Guarantor without proceeding against any other Guarantor, the
Borrower, against any security for the Guaranteed Obligations, or under any
other guaranty covering all or a portion of the Guaranteed Obligations.

                  2. Additionally, each Guarantor, jointly and severally,
unconditionally, absolutely and irrevocably, guarantees the payment of any and
all Guaranteed Obligations whether or not due or payable by the Borrower upon
the occurrence in respect of the Borrower of any of the events specified in
Section 10.05 of the Credit Agreement, and unconditionally, absolutely and
irrevocably, jointly and severally, promises to pay such Guaranteed Obligations
to the Secured Creditors, or order, on demand, in legal tender of the United
States. This Guaranty shall constitute a guaranty of payment, and not of
collection.


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                  3. The liability of each Guarantor hereunder is primary,
absolute and unconditional and is exclusive and independent of any security for
or other guaranty of the indebtedness of the Borrower whether executed by such
Guarantor, any other Guarantor, any other guarantor or by any other party, and
the liability of each Guarantor hereunder shall not be affected or impaired by
any circumstance or occurrence whatsoever, including, without limitation: (a)
any direction as to application of payment by the Borrower or by any other
party, (b) any other continuing or other guaranty, undertaking or maximum
liability of a guarantor or of any other party as to the Guaranteed Obligations,
(c) any payment on or in reduction of any such other guaranty or undertaking
(other than a payment in full in cash of all Guaranteed Obligations), (d) any
dissolution, termination or increase, decrease or change in personnel by the
Borrower, (e) any payment made to any Secured Creditor on the indebtedness which
any Secured Creditor repays the Borrower pursuant to court order in any
bankruptcy, reorganization, arrangement, moratorium or other debtor relief
proceeding, and each Guarantor waives any right to the deferral or modification
of its obligations hereunder by reason of any such proceeding, (f) any action or
inaction by the Secured Creditors as contemplated in Section 6 hereof or (g) any
invalidity, irregularity or unenforceability of all or any part of the
Guaranteed Obligations or of any security therefor.

                  4. The obligations of each Guarantor hereunder are independent
of the obligations of any other Guarantor, any other guarantor or the Borrower,
and a separate action or actions may be brought and prosecuted against each
Guarantor whether or not action is brought against any other Guarantor, any
other guarantor or the Borrower and whether or not any other Guarantor, any
other guarantor or the Borrower be joined in any such action or actions. Each
Guarantor waives, to the fullest extent permitted by law, the benefits of any
statute of limitations affecting its liability hereunder or the enforcement
thereof. Any payment by the Borrower or other circumstance which operates to
toll any statute of limitations as to the Borrower shall operate to toll the
statute of limitations as to each Guarantor.

                  5. Each Guarantor hereby waives notice of acceptance of this
Guaranty and notice of any liability to which it may apply, and waives
promptness, diligence, presentment, demand of payment, protest, notice of
dishonor or nonpayment of any such liabilities, suit or taking of other action
by the Administrative Agent or any other Secured Creditor against, and any other
notice to, any party liable thereon (including such Guarantor, any other
Guarantor, any other guarantor, the Borrower).

                  6. Any Secured Creditor may at any time and from time to time
without the consent of, or notice to, any Guarantor, without incurring
responsibility to such Guarantor, without impairing or releasing the obligations
of such Guarantor hereunder, upon or without any terms or conditions and in
whole or in part:

                  (a) change the manner, place or terms of payment of, and/or
         change or extend the time of payment of, renew, alter or increase, any
         of the Guaranteed Obligations (including any increase or decrease in
         the rate of interest thereon), any security therefor, or any liability
         incurred directly or indirectly in respect thereof, and the guaranty
         herein


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         made shall apply to the Guaranteed Obligations as so changed,
         extended, renewed or altered;

                  (b) take and hold security for the payment of the Guaranteed
         Obligations and sell, exchange, release, surrender, impair, realize
         upon or otherwise deal with in any manner and in any order any property
         by whomsoever at any time pledged or mortgaged to secure, or howsoever
         securing, the Guaranteed Obligations or any liabilities (including any
         of those hereunder) incurred directly or indirectly in respect thereof
         or hereof, and/or any offset thereagainst;

                  (c) exercise or refrain from exercising any rights against the
         Borrower, any other Credit Party, any Subsidiary thereof or otherwise
         act or refrain from acting;

                  (d) release or substitute any one or more endorsers,
         Guarantors, other guarantors, the Borrower or other obligors;

                  (e) settle or compromise any of the Guaranteed Obligations,
         any security therefor or any liability (including any of those
         hereunder) incurred directly or indirectly in respect thereof or
         hereof, and may subordinate the payment of all or any part thereof to
         the payment of any liability (whether due or not) of the Borrower to
         creditors of the Borrower other than the Secured Creditors;

                  (f) apply any sums by whomsoever paid or howsoever realized to
         any liability or liabilities of the Borrower to the Secured Creditors
         regardless of what liabilities of the Borrower remain unpaid;

                  (g) consent to or waive any breach of, or any act, omission or
         default under, any of the Interest Rate Protection Agreements or Other
         Hedging Agreements, the Credit Documents or any of the instruments or
         agreements referred to therein, or otherwise amend, modify or
         supplement any of the Interest Rate Protection Agreements or Other
         Hedging Agreements, the Credit Documents or any of such other
         instruments or agreements;

                  (h) act or fail to act in any manner referred to in this
         Guaranty which may deprive such Guarantor of its right to subrogation
         against the Borrower to recover full indemnity for any payments made
         pursuant to this Guaranty, to the extent permitted by applicable law;
         and/or

                  (i) take any other action which would, under otherwise
         applicable principles of common law, give rise to a legal or equitable
         discharge of such Guarantor from its liabilities under this Guaranty.

                  7. This Guaranty is a continuing one and all liabilities to
which it applies or may apply under the terms hereof shall be conclusively
presumed to have been created in reliance hereon. No failure or delay on the
part of any Secured Creditor in exercising any right,


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power or privilege hereunder shall operate as a waiver thereof, nor shall any
single or partial exercise of any right, power or privilege hereunder
preclude any other or further exercise thereof or the exercise of any other
right, power or privilege. The rights and remedies herein expressly specified
are cumulative and not exclusive of any rights or remedies which any Secured
Creditor would otherwise have. No notice to or demand on any Guarantor in any
case shall entitle such Guarantor to any other further notice or demand in
similar or other circumstances or constitute a waiver of the rights of any
Secured Creditor to any other or further action in any circumstances without
notice or demand. It is not necessary for any Secured Creditor to inquire
into the capacity or powers of the Borrower or the officers, directors,
partners or agents acting or purporting to act on its behalf, and any
indebtedness made or created in reliance upon the professed exercise of such
powers shall be guaranteed hereunder.

                  8. Any indebtedness of the Borrower now or hereafter held by
any Guarantor is hereby subordinated to the indebtedness of the Borrower or to
the Secured Creditors, and if the Administrative Agent or the Collateral Agent
so requests, after the occurrence and during the continuance of an Event of
Default, such indebtedness of the Borrower to any Guarantor shall be collected,
enforced and received by such Guarantor as trustee for the Secured Creditors and
be paid over to the Secured Creditors on account of the indebtedness of the
Borrower to the Secured Creditors, but without affecting or impairing in any
manner the liability of such Guarantor under the other provisions of this
Guaranty. Without limiting the generality of the foregoing, each Guarantor
hereby agrees with the Secured Creditors that it will not exercise any right of
subrogation which it may at any time otherwise have as a result of this Guaranty
(whether contractual, under Section 509 of the Bankruptcy Code or otherwise)
until all Guaranteed Obligations have been irrevocably paid in full in cash.

                  9. (a) Each Guarantor waives any right (except as shall be
required by applicable law and cannot be waived) to require the Secured
Creditors to: (i) proceed against the Borrower, any other Guarantor, any other
guarantor of the Guaranteed Obligations or any other party; (ii) proceed against
or exhaust any security held from the Borrower, any other Guarantor, any other
guarantor of the Guaranteed Obligations or any other party; or (iii) pursue any
other remedy in the Secured Creditors' power whatsoever. Each Guarantor waives
any defense based on or arising out of any defense of the Borrower, any other
Guarantor, any other guarantor of the Guaranteed Obligations or any other party
other than payment of the Guaranteed Obligations (but only to the extent of such
payment), including, without limitation, any defense based on or arising out of
the disability of the Borrower, any other Guarantor, any other guarantor of the
Guaranteed Obligations or any other party, or the unenforceability of the
Guaranteed Obligations or any part thereof from any cause, or the cessation from
any cause of the liability of the Borrower other than payment of the Guaranteed
Obligations. The Secured Creditors may, at their election and to the extent
permitted by applicable law, foreclose on any security held by the
Administrative Agent, the Collateral Agent or the other Secured Creditors by one
or more judicial or nonjudicial sales, whether or not every aspect of any such
sale is commercially reasonable, or exercise any other right or remedy the
Secured Creditors may have against the Borrower or any other party, or any
security, without affecting or impairing in any way the liability of any
Guarantor hereunder except to the extent the Guaranteed Obligations have been


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paid in full in cash. Each Guarantor waives any defense arising out of any such
election by the Secured Creditors, even though such election operates to impair
or extinguish any right of reimbursement or subrogation or other right or remedy
of such Guarantor against the Borrower or any other party or any security.

                  (b) Each Guarantor waives all presentments, demands for
performance, protests and notices, including, without limitation, notices of
nonperformance, notices of protest, notices of dishonor, notices of acceptance
of this Guaranty, and notices of the existence, creation or incurring of new or
additional indebtedness. Each Guarantor assumes all responsibility for being and
keeping itself informed of the Borrower's financial condition and assets, and of
all other circumstances bearing upon the risk of nonpayment of the Guaranteed
Obligations and the nature, scope and extent of the risks which such Guarantor
assumes and incurs hereunder, and agrees that the Secured Creditors shall have
no duty to advise any Guarantor of information known to them regarding such
circumstances or risks.

                  (c) Each Guarantor hereby acknowledges and affirms that it
understands that to the extent the Guaranteed Obligations are secured by Real
Property located in the State of California, such Guarantor shall be liable for
the full amount of its liability hereunder notwithstanding foreclosure on such
Real Property by trustee sale or any other reason impairing such Guarantor's or
any Secured Creditors' right to proceed against the Borrower or any other
guarantor of the Guaranteed Obligations. In accordance with Section 2856 of the
California Civil Code, each Guarantor hereby waives:

                  (i) all rights of subrogation, reimbursement, indemnification,
         and contribution and any other rights and defenses that are or may
         become available to such Guarantor by reason of Sections 2787 to 2855,
         inclusive, 2899 and 3433 of the California Civil Code;

                  (ii) all rights and defenses that such Guarantor may have
         because the Guaranteed Obligations are secured by Real Property located
         in the State of California. This means, among other things: (A) the
         Secured Creditors may collect from such Guarantors without first
         foreclosing on any real or personal property collateral pledged by the
         Borrower or any other Credit Party; and (B) if the Secured Creditors
         foreclose on any Real Property collateral pledged by the Borrower or
         any other Credit Party, (1) the amount of the Guaranteed Obligations
         may be reduced only by the price for which that collateral is sold at
         the foreclosure sale, even if the collateral is worth more than the
         sale price, and (2) the Secured Creditors may collect from such
         Guarantor even if the Secured Creditors, by foreclosing on the Real
         Property collateral, have destroyed any right such Guarantor may have
         to collect from the Borrower. This is an unconditional and irrevocable
         waiver of any rights and defenses such Guarantor may have because the
         Guaranteed Obligations are secured by Real Property. These rights and
         defenses include, but are not limited to, any rights or defenses based
         upon Section 580a, 580b, 580d or 726 of the California Code of Civil
         Procedure; and


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                  (iii) all rights and defenses arising out of an election of
         remedies by the Secured Creditors, even though that election of
         remedies, such as a nonjudicial foreclosure with respect to security
         for the Guaranteed Obligations, has destroyed such Guarantor's rights
         of subrogation and reimbursement against the Borrower by the operation
         of Section 580d of California the Code of Civil Procedure or otherwise.

                  Each Guarantor warrants and agrees that each of the waivers
set forth above is made with full knowledge of its significance and consequences
and that if any of such waivers are determined to be contrary to any applicable
law or public policy, such waivers shall be effective only to the maximum extent
permitted by law.

                  10. The Secured Creditors agree that this Guaranty may be
enforced only by the action of the Administrative Agent or the Collateral Agent
and that no other Secured Creditors shall have any right individually to seek to
enforce or to enforce this Guaranty or to realize upon the security to be
granted by the Security Documents, it being understood and agreed that such
rights and remedies may be exercised by the Administrative Agent or the
Collateral Agent or, after all the Credit Document Obligations have been paid in
full, by the holders of at least a majority of the outstanding Other
Obligations, as the case may be, for the benefit of the Secured Creditors upon
the terms of this Guaranty and the Security Documents. The Secured Creditors
further agree that this Guaranty may not be enforced against any director,
officer, employee, partner or stockholder of any Guarantor (except to the extent
such partner or stockholder is also a Guarantor hereunder).

                  11. In order to induce the Lenders to make Loans to, and issue
Letters of Credit for the account of, the Borrower pursuant to the Credit
Agreement, and in order to induce the Other Creditors to execute, deliver and
perform the Interest Rate Protection Agreements or Other Hedging Agreements,
each Guarantor represents, warrants and covenants that:

                  (a) Such Guarantor (i) is duly organized, validly existing and
         in good standing under the laws of the jurisdiction of its
         organization, (ii) has the Company power and authority to own its
         property and assets and to transact the business in which it is engaged
         and presently proposes to engage and (iii) is duly qualified and is
         authorized to do business and is in good standing in each jurisdiction
         where the conduct of its business requires such qualification except
         for failures to be so qualified which, individually or in the
         aggregate, could not reasonably be expected to have a material adverse
         effect on the business, operations, financial condition or prospects of
         Holdings and its Subsidiaries taken as a whole.

                  (b) Such Guarantor has the Company power and authority to
         execute, deliver and perform the terms and provisions of this Guaranty
         and each other Credit Document to which it is a party and has taken all
         necessary corporate action to authorize the execution, delivery and
         performance by it of this Guaranty and each such other Credit Document.
         Such Guarantor has duly executed and delivered this Guaranty and each
         other Credit Document to which it is a party, and this Guaranty and
         each such other Credit Document


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         constitutes the legal, valid and binding obligation of such
         Guarantor enforceable in accordance with its terms, except to the
         extent that the enforceability hereof or thereof may be limited by
         applicable bankruptcy, insolvency, reorganization, moratorium or other
         similar laws generally affecting creditors' rights and by equitable
         principles (regardless of whether enforcement is sought in equity or
         at law).

                  (c) Neither the execution, delivery or performance by such
         Guarantor of this Guaranty or any other Credit Document to which it is
         a party, nor compliance by it with the terms and provisions hereof and
         thereof, will materially or adversely (i) contravene any provision of
         any applicable law, statute, rule or regulation or any applicable
         order, writ, injunction or decree of any court or governmental
         instrumentality, (ii) conflict with or result in any breach of any of
         the terms, covenants, conditions or provisions of, or constitute a
         default under, or result in the creation or imposition of (or the
         obligation to create or impose) any Lien (except pursuant to the
         Security Documents) upon any of the property or assets of such
         Guarantor or any of its Subsidiaries pursuant to the terms of any
         material indenture, mortgage, deed of trust, loan agreement, credit
         agreement, or any other material agreement, contract or instrument to
         which such Guarantor or any of its Subsidiaries is a party or by which
         it or any of its property or assets is bound or to which it may be
         subject or (iii) violate any provision of the certificate of
         incorporation or by-laws (or equivalent organizational documents) of
         such Guarantor or any of its Subsidiaries.

                  (d) No order, consent, approval, license, authorization or
         validation of, or filing, recording or registration with (except as
         have been obtained or made), or exemption by, any governmental or
         public body or authority, or any subdivision thereof, is required to
         authorize, or is required for, (i) the execution, delivery and
         performance of this Guaranty by such Guarantor or any other Credit
         Document to which such Guarantor is a party or (ii) the legality,
         validity, binding effect or enforceability of this Guaranty or any
         other Credit Document to which such Guarantor is a party.

                  (e) There are no actions, suits or proceedings pending or
         threatened (i) with respect to this Guaranty or any other Credit
         Document to which such Guarantor is a party or (ii) with respect to
         such Guarantor that could reasonably be expected to materially and
         adversely affect (a) the business, operations, financial condition or
         prospects of Holdings and its Subsidiaries taken as a whole or (b) the
         rights or remedies of the Secured Creditors hereunder or under the
         other Credit Documents to which such Guarantor is a party or the
         ability of such Guarantor to perform its respective obligations to the
         Secured Creditors hereunder and under the other Credit Documents to
         which it is a party.

                  12. Each Guarantor covenants and agrees that on and after the
Effective Date and until the termination of the Total Revolving Loan Commitment
and all Interest Rate Protection Agreements and Other Hedging Agreements
constituting a Guaranteed Obligation of the Borrower and when no Note or Letter
of Credit remains outstanding and all Guaranteed Obligations have been paid in
full, such Guarantor will comply, and will cause each of its


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Subsidiaries to comply, with all of the applicable provisions, covenants and
agreements contained in Sections 8 and 9 of the Credit Agreement, and will
take, or will refrain from taking, as the case may be, all actions that are
necessary to be taken or not taken so that it is not in violation of any
provision, covenant or agreement contained in Section 8 or 9 of the Credit
Agreement, and so that no Default or Event of Default, is caused by the
actions of such Guarantor or any of its Subsidiaries.

                  13. The Guarantors hereby jointly and severally agree to pay
all reasonable out-of-pocket costs and expenses of each Secured Creditor in
connection with the enforcement of this Guaranty and of the Administrative Agent
in connection with any amendment, waiver or consent relating hereto (including
in each case, without limitation, the reasonable fees and disbursements of
counsel employed by each Secured Creditor).

                  14. This Guaranty shall be binding upon each Guarantor and its
successors and assigns and shall inure to the benefit of the Secured Creditors
and their successors and assigns.

                  15. Neither this Guaranty nor any provision hereof may be
changed, waived, discharged or terminated except with the written consent of
each Guarantor directly affected thereby and with the written consent of the
Required Secured Creditors (as defined in the Security Agreement); PROVIDED,
that any change, waiver, modification or variance affecting the rights and
benefits of a single Class (as defined below) of Secured Creditors (and not all
Secured Creditors in a like or similar manner) shall also require the written
consent of the Requisite Creditors (as defined below) of such Class of Secured
Creditors (it being understood that the addition or release of any Guarantor
hereunder shall not constitute a change, waiver, discharge or termination
affecting any Guarantor other than the Guarantor so added or released). For the
purpose of this Guaranty, the term "Class" shall mean each class of Secured
Creditors, I.E., whether (x) the Lender Creditors as holders of the Credit
Document Obligations or (y) the Other Creditors as the holders of the Other
Obligations. For the purpose of this Guaranty, the term "Requisite Creditors" of
any Class shall mean (x) with respect to the Credit Document Obligations, the
Required Lenders and (y) with respect to the Other Obligations, the holders of
at least a majority amount of all obligations outstanding from time to time
under the Interest Rate Protection or Other Hedging Agreements, but only if such
Interest Rate Protection Agreement or Other Hedging Agreement constitutes a
Guaranteed Obligation of the Borrower.

                  16. Each Guarantor acknowledges that an executed (or
conformed) copy of each of the Credit Documents and Interest Rate Protection
Agreements or Other Hedging Agreements has been made available to its principal
executive officers and such officers are familiar with the contents thereof.

                  17. In addition to any rights now or hereafter granted under
applicable law (including, without limitation, Section 151 of the New York
Debtor and Secured Creditor Law) and not by way of limitation of any such
rights, upon the occurrence and during the continuance of an Event of Default
(such term to mean and include any "Event of Default" as defined in the


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Credit Agreement or any payment default under any Interest Rate Protection
Agreement or Other Hedging Agreement, but only if such Interest Rate
Protection Agreement or Other Hedging Agreement constitutes a Guaranteed
Obligation of the Borrower, continuing after any applicable grace period),
each Secured Creditor is hereby authorized, at any time or from time to time,
without notice to any Guarantor or to any other Person, any such notice being
expressly waived, to set off and to appropriate and apply any and all
deposits (general or special) and any other indebtedness at any time held or
owing by such Secured Creditor to or for the credit or the account of such
Guarantor, against and on account of the obligations and liabilities of such
Guarantor to such Secured Creditor under this Guaranty, irrespective of
whether or not such Secured Creditor shall have made any demand hereunder and
although said obligations, liabilities, deposits or claims, or any of them,
shall be contingent or unmatured. Notwithstanding anything to the contrary
contained in this Section 17, no Secured Creditor shall exercise any such
right of set-off without the prior consent of the Administrative Agent or the
Required Secured Creditors so long as the Guaranteed Obligations shall be
secured by any Real Property located in the State of California, it being
understood and agreed, however, that this sentence is for the sole benefit of
the Secured Creditors and may be amended, modified or waived in any respect
by the Required Secured Creditors without the requirements of prior notice to
or consent by any Credit Party and does not constitute a waiver of any rights
against any Credit party or against any Collateral.

                  18. All notices, requests, demands or other communications
pursuant hereto shall be deemed to have been duly given or made when delivered
to the Person to which such notice, request, demand or other communication is
required or permitted to be given or made under this Guaranty, addressed to such
party at (i) in the case of any Lender Creditor, as provided in the Credit
Agreement, (ii) in the case of any Guarantor, at the address set forth opposite
such Guarantor's signature below and (iii) in the case of any Other Creditor, at
such address as such Other Creditor shall have specified in writing to the
Guarantors; or in any case at such other address as any of the Persons listed
above may hereafter notify the others in writing.

                  19. If claim is ever made upon any Secured Creditor for
repayment or recovery of any amount or amounts received in payment or on account
of any of the Guaranteed Obligations and any of the aforesaid payees repays all
or part of said amount by reason of (i) any judgment, decree or order of any
court or administrative body having jurisdiction over such payee or any of its
property or (ii) any settlement or compromise of any such claim effected by such
payee with any such claimant (including the Borrower) then and in such event
each Guarantor agrees that any such judgment, decree, order, settlement or
compromise shall be binding upon such Guarantor, notwithstanding any revocation
hereof or other instrument evidencing any liability of the Borrower, and such
Guarantor shall be and remain liable to the aforesaid payees hereunder for the
amount so repaid or recovered to the same extent as if such amount had never
originally been received by any such payee.

                  20. (a) THIS GUARANTY AND THE RIGHTS AND OBLIGATIONS OF THE
SECURED CREDITORS AND OF THE UNDERSIGNED HEREUNDER SHALL BE GOVERNED BY AND
CONSTRUED IN ACCORDANCE WITH THE LAW OF THE STATE


                                       10

<PAGE>

OF NEW YORK. Any legal action or proceeding with respect to this Guaranty or
any other Credit Document to which any Guarantor is a party may be brought in
the courts of the State of New York or of the United States of America for
the Southern District of New York, and, by execution and delivery of this
Guaranty, each Guarantor hereby irrevocably accepts for itself and in respect
of its property, generally and unconditionally, the jurisdiction of the
aforesaid courts. Each Guarantor hereby further irrevocably waives any claim
that any such court lacks personal jurisdiction over such Guarantor, and
agrees not to plead or claim in any legal action or proceeding with respect
to this Guaranty or any other Credit Document to which such Guarantor is a
party brought in any of the aforesaid courts that any such court lacks
personal jurisdiction over such Guarantor. Each Guarantor further irrevocably
consents to the service of process out of any of the aforementioned courts in
any such action or proceeding by the mailing of copies thereof by registered
or certified mail, postage prepaid, to such Guarantor at its address set
forth opposite its signature below, such service to become effective 30 days
after such mailing. Each Guarantor hereby irrevocably waives any objection to
such service of process and further irrevocably waives and agrees not to
plead or claim in any action or proceeding commenced hereunder or under any
other Credit Document to which such Guarantor is a party that such service of
process was in any way invalid or ineffective. Nothing herein shall affect
the right of any of the Secured Creditors to serve process in any other
manner permitted by law or to commence legal proceedings or otherwise proceed
against each Guarantor in any other jurisdiction.

                  (b) Each Guarantor hereby irrevocably waives (to the fullest
extent permitted by applicable law) any objection which it may now or hereafter
have to the laying of venue of any of the aforesaid actions or proceedings
arising out of or in connection with this Guaranty or any other Credit Document
to which such Guarantor is a party brought in the courts referred to in clause
(a) above and hereby further irrevocably waives and agrees not to plead or claim
in any such court that such action or proceeding brought in any such court has
been brought in an inconvenient forum.

                  (c) EACH GUARANTOR AND EACH SECURED CREDITOR (BY ITS
ACCEPTANCE OF THE BENEFITS OF THIS GUARANTY) HEREBY IRREVOCABLY WAIVES ALL
RIGHTS TO A TRIAL BY JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM ARISING OUT
OF OR RELATING TO THIS GUARANTY, THE OTHER CREDIT DOCUMENTS TO WHICH SUCH
GUARANTOR IS A PARTY OR THE TRANSACTIONS CONTEMPLATED HEREBY OR THEREBY.

                  21. In the event that all of the capital stock of one or more
Guarantors is sold or otherwise disposed of or liquidated in compliance with the
requirements of Section 9.02 of the Credit Agreement (or such sale or other
disposition has been approved in writing by the Required Secured Creditors) and
the proceeds of such sale, disposition or liquidation are applied in accordance
with the provisions of the Credit Agreement, to the extent applicable, such
Guarantor shall upon consummation of such sale or other disposition (except to
the extent that such sale or disposition is to the Borrower or another
Subsidiary thereof) be released from this Guaranty automatically and without
further action and this Guaranty shall, as to each such Guarantor or


                                       11

<PAGE>

Guarantors, terminate, and have no further force or effect, and upon the
request of Borrower, the Administrative Agent, on behalf of the Secured
Creditors, shall acknowledge, in writing, the termination of this Guaranty
(it being understood and agreed that the sale of one or more Persons that
own, directly or indirectly, all of the capital stock of any Guarantor shall
be deemed to be a sale of such Guarantor for the purposes of this Section 21).

                  22. At any time a payment in respect of the Guaranteed
Obligations is made under this Guaranty, the right of contribution of each
Guarantor against each other Guarantor shall be determined as provided in the
immediately following sentence, with the right of contribution of each Guarantor
to be revised and restated as of each date on which a payment (a "Relevant
Payment") is made on the Guaranteed Obligations under this Guaranty. At any time
that a Relevant Payment is made by a Guarantor that results in the aggregate
payments made by such Guarantor in respect of the Guaranteed Obligations to and
including the date of the Relevant Payment exceeding such Guarantor's
Contribution Percentage (as defined below) of the aggregate payments made by all
Guarantors in respect of the Guaranteed Obligations to and including the date of
the Relevant Payment (such excess, the "Aggregate Excess Amount"), each such
Guarantor shall have a right of contribution against each other Guarantor who
has made payments, in respect of the Guaranteed Obligations to and including the
date of the Relevant Payment, in an aggregate amount less than such other
Guarantor's Contribution Percentage of the aggregate payments made to and
including the date of the Relevant Payment by all Guarantors in respect of the
Guaranteed Obligations (the aggregate amount of such deficit, the "Aggregate
Deficit Amount") in an amount equal to (x) a fraction the numerator of which is
the Aggregate Excess Amount of such Guarantor and the denominator of which is
the Aggregate Excess Amount of all Guarantors multiplied by (y) the Aggregate
Deficit Amount of such other Guarantor. A Guarantor's right of contribution
pursuant to the preceding sentences shall arise at the time of each computation,
subject to adjustment to the time of any subsequent computation; PROVIDED, that
no Guarantor may take any action to enforce such right until the Guaranteed
Obligations have been irrevocably paid in full in cash, it being expressly
recognized and agreed by all parties hereto that any Guarantor's right of
contribution arising pursuant to this Section 22 against any other Guarantor
shall be expressly junior and subordinate to such other Guarantor's obligations
and liabilities in respect of the Guaranteed Obligations and any other
obligations owing under this Guaranty. As used in this Section 22: (i) each
Guarantor's "Contribution Percentage" shall mean the percentage obtained by
dividing (x) the Adjusted Net Worth (as defined below) of such Guarantor by (y)
the aggregate Adjusted Net Worth of all Guarantors; (ii) the "Adjusted Net
Worth" of each Guarantor shall mean the greater of (x) the Net Worth (as defined
below) of such Guarantor and (y) zero; and (iii) the "Net Worth" of each
Guarantor shall mean the amount by which the fair salable value of such
Guarantor's assets on the date of any Relevant Payment exceeds its existing
debts and other liabilities (including contingent liabilities, but without
giving effect to any Guaranteed Obligations arising under this Guaranty) on such
date. All parties hereto recognize and agree that, except for any right of
contribution arising pursuant to this Section 22, each Guarantor who makes any
payment in respect of the Guaranteed Obligations shall have no right of
contribution or subrogation against any other Guarantor in respect of such
payment until all of the Guaranteed Obligations have been irrevocably paid in
full in cash. Each of the Guarantors recognizes and acknowledges that the rights
to contribution


                                       12

<PAGE>

arising hereunder shall constitute an asset in favor of the party entitled to
such contribution. In this connection, each Guarantor has the right to waive
its contribution right against any Guarantor to the extent that after giving
effect to such waiver such Guarantor would remain solvent, in the
determination of the Required Lenders.

                  23. Each Guarantor and each Secured Creditor (by its
acceptance of the benefits of this Guaranty) hereby confirms that it is its
intention that this Guaranty not constitute fraudulent transfer or conveyance
for purposes of the Bankruptcy Code, the Uniform Fraudulent Conveyance Act of
any similar Federal or state law. To effectuate the foregoing intention, each
Guarantor and each Secured Creditor (by its acceptance of the benefits of this
Guaranty) hereby irrevocably agrees that the Guaranteed Obligations guaranteed
by such Guarantor shall be limited to such amount as will, after giving effect
to such maximum amount and all other (contingent or otherwise) liabilities of
such Guarantor that are relevant under such laws, and after giving effect to any
rights to contribution pursuant to any agreement providing for an equitable
contribution among such Guarantor and the other Guarantors, result in the
Guaranteed Obligations of such Guarantor in respect of such maximum amount not
constituting a fraudulent transfer or conveyance.

                  24. This Guaranty may be executed in any number of
counterparts and by the different parties hereto on separate counterparts, each
of which when so executed and delivered shall be an original, but all of which
shall together constitute one and the same instrument. A set of counterparts
executed by all the parties hereto shall be lodged with the Guarantors and the
Administrative Agent.

                  25. All payments made by any Guarantor hereunder will be made
without setoff, counterclaim or other defense and on the same basis as payments
are made by the Borrower under Sections 4.03 and 4.04 of the Credit Agreement.

                  26. It is understood and agreed that any Subsidiary of
Holdings that is required to execute a counterpart of this Guaranty after the
date hereof pursuant to the Credit Agreement shall automatically become a
Guarantor hereunder by executing a counterpart hereof and delivering the same to
the Administrative Agent.

                                      * * *


                                       13

<PAGE>


                  IN WITNESS WHEREOF, each Guarantor has caused this Guaranty to
be executed and delivered as of the date first above written.

<TABLE>
<S>                                         <C>
Address:

c/o Information Holdings, Inc.              CRC PRESS, L.L.C.
2777 Summer Street                           as a Guarantor
Suite 209
Stamford, CT  06905
Attn:  Vincent Chippari                     By:__________________________
Telephone No.:  (203) 961-9208                 Name:
Telecopier No.:  (203) 961-1431                Title:



c/o Information Holdings, Inc.              MICROPATENT, L.L.C.
2777 Summer Street                           as a Guarantor
Suite 209
Stamford, CT  06905
Attn:  Vincent Chippari                     By:__________________________
Telephone No.:  (203) 961-9208                 Name:
Telecopier No.:  (203) 961-1431                Title:



c/o Information Holdings, Inc.              MASTER DATA CENTER, INC.
2777 Summer Street                           as a Guarantor
Suite 209
Stamford, CT  06905
Attn:  Vincent Chippari                     By:__________________________
Telephone No.:  (203) 961-9208                 Name:
Telecopier No.:  (203) 961-1431                Title:



c/o Information Holdings, Inc.              CRC PRESS UK, L.L.C.
2777 Summer Street                           as a Guarantor
Suite 209
Stamford, CT  06905
Attn:  Vincent Chippari                     By:__________________________
Telephone No.:  (203) 961-9208                 Name:
Telecopier No.:  (203) 961-1431                Title:


                                       14

<PAGE>

c/o Information Holdings, Inc.              OPTIPAT, INC.
2777 Summer Street                           as a Guarantor
Suite 209
Stamford, CT  06905
Attn:  Vincent Chippari                     By:__________________________
Telephone No.:  (203) 961-9208                 Name:
Telecopier No.:  (203) 961-1431                Title:




<S>                                         <C>
c/o Information Holdings, Inc.              MICROPATENT UK, L.L.C.
2777 Summer Street                           as a Guarantor
Suite 209
Stamford, CT  06905
Attn:  Vincent Chippari                     By:__________________________
Telephone No.:  (203) 961-9208                 Name:
Telecopier No.:  (203) 961-1431                Title:



Accepted and Agreed to:


BANKERS TRUST COMPANY,
 as Administrative Agent

By______________________
    Name:
    Title:
</TABLE>


                                       15