Document:

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                                                                   EXHIBIT 10.13

                      ASSIGNMENT OF STOCK WARRANT RIGHTS

     This Assignment of Stock Warrant Rights (this "Assignment") is made
effective as of May 31, 2000, by and among Crosby Capital LLC, a Texas limited
liability company ("Warrant Rights Holder"), and Aviva Petroleum Inc., a Texas
corporation ("Parent").

                                 R E C I T A L

     WHEREAS, pursuant to Sections 1.03 and 5.03 of that certain Loan,
Settlement and Acquisition Agreement dated as of May 31, 2000 (the "Purchase
Agreement"), by and among Warrant Rights Holder, and Parent, Aviva America,
Inc., a Delaware corporation ("Aviva America"), Aviva Operating, Inc., a
Delaware corporation ("Aviva Operating"), Aviva Overseas, Inc., a Delaware
corporation ("Aviva Overseas"), Neo Energy Inc., a Texas corporation ("Neo"),
Garnet Resources Corp., a Delaware corporation ("Garnet"), Argosy Energy, Inc.,
a Delaware corporation ("Argosy Energy"), and Argosy Energy International, a
Utah limited partnership ("Argosy International"), Warrant Rights Holder agreed
to transfer and deliver to Parent Warrant Rights Holder's right to purchase
1,500,000 shares of Parent's common stock (the "Warrant Rights").

                               A G R E E M E N T

     NOW, THEREFORE, in consideration of the promises herein and in the Purchase
Agreement, and other good and valuable consideration, the receipt and
sufficiency of which are hereby acknowledged, the Warrant Rights Holder and
Parent hereby agree as follows:

     1.   Transfer of Warrant Rights. Warrant Rights Holder hereby conveys,
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transfers, assigns, grants, sells and delivers, to Parent, and Parent acquires,
accepts and purchases, all of Warrant Rights Holder's right, title and interest
in and to the Warrant Rights.

     2.   Assumption. Parent hereby assumes and accepts the Warrant Rights.
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     3.   Delivery. Warrant Rights Holder is delivering to Parent simultaneously
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herewith that certain Affidavit of Lost Stock Warrants executed by ING (U.S.)
Capital LLC on April 27, 2000, and Parent hereby acknowledges receipt of same.

     4.   Further Assurances. Warrant Rights Holder shall execute and deliver to
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Parent such further documents and instruments, and take such other action, that
may be reasonably requested by Parent to evidence this conveyance, transfer and
assignment of the Warrant Rights.

     5.   Definitions. All capitalized terms not otherwise defined herein shall
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have the meaning ascribed to them in the Purchase Agreement.

     6.   Inurement. The conveyance, assignment and transfer herein shall be
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effective as of the date hereof, and shall inure to the benefit of and be
binding upon the parties hereto and their successors or permitted assigns.
However, nothing in this Assignment, express or implied, shall give any other
person any benefit or any legal or equitable right or remedy with respect
hereto.
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     7.   Conveyance Subject to the Purchase Agreement. This conveyance is made
          --------------------------------------------
pursuant to the Purchase Agreement and is subject to the terms thereof.

     8.   Counterparts. This Assignment may be separately executed in
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counterparts, each of which when so executed shall be deemed to constitute one
and the same agreement. Such execution and delivery may be accomplished by
facsimile transmission.

     9.   Governing Law. This Assignment shall be governed by and construed in
          -------------
accordance with the laws of the State of Texas, without regard to principles of
conflicts of law thereof.

                           [SIGNATURES ON NEXT PAGE]

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     IN WITNESS WHEREOF, each of the undersigned has caused this Assignment to
be executed as of the day and year first written above.

                                        AVIVA PETROLEUM, INC.

                                        By: /s/ R. Suttill
                                            --------------
                                            President

                                        CROSBY CAPITAL, LLC

                                        By: /s/ Jay A. Chaffee
                                            ------------------
                                            Jay A. Chaffee
                                            President

                                       3<PAGE>

                                                                   Exhibit 10(i)
                                                                   -------------

                             SUBSCRIPTION AGREEMENT

equip2move.com Corporation
c/o Koster Industries Inc.
555 Broadhollow Road
Melville, NY 11747
Attention:  Russell Koster

Ladies and Gentlemen:

          Enviro-Clean of America, Inc. (the "Subscriber") desires to purchase
shares of Class B common stock, par value $0.001 per share (the "Common Stock")
of equip2move.com Corporation (the "Seller").  The Subscriber and the Seller
hereby agree as follows:

I.   Subscription. The Subscriber hereby subscribes for and agrees to accept
     ------------
from the Seller the number of shares of the Seller's Common Stock (the "Shares")
set forth in the Subscriber Signature Page attached hereto and agrees to pay the
purchase price of US $0.25 per share. The aggregate purchase price (the
"Purchase Price") for the number of Shares subscribed for has been set forth in
the Subscriber Signature Page. As a condition of the purchase, the Subscriber
hereby agrees to transfer an aggregate of 70,000 shares of common stock of
b2bstores.com, Inc. to the Seller. As a further condition of the purchase, the
Subscriber hereby agrees to provide the Seller with funds equal to not less than
$150,000 and not more than $250,000 for the purpose of creating, designing and
implementing the functionality of the Seller's web site.

II.  Purchase Procedure. The Subscriber acknowledges that, in order to subscribe
     ------------------
for the Shares, such Subscriber must, and such Subscriber does hereby, deliver
to the Seller:

     A.  Two (2) executed counterparts of the Subscriber Signature Page attached
     to this Subscription Agreement (this "Agreement"); and

     B.  Two (2) completed copies of the Subscriber Questionnaire attached
     hereto as Exhibit A; and

     C.  Two (2) executed counterparts of the signature page to the
     Stockholders' Agreement (as herein defined); and

     D.  Payment of the Purchase Price to the Seller by check or wire transfer
     of immediately available funds for a value date no less than two (2)
     business days prior to the date to be specified by the Seller as the
     closing date for the offering contemplated hereby. The Seller will notify
     Subscribers of the closing date and provide Subscribers with wire transfer
     instructions under separate cover.
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III. Acceptance Procedure. All subscription payments, when received, will be
     ---------------------
held in an account of the Seller, which account information will be provided to
the Subscriber.

IV.  Representations of Subscriber. By executing this Agreement, the Subscriber
     -----------------------------
makes the following representations, declarations and warranties to the Seller,
with the intent and understanding that the Seller will rely thereon:

     A.  Such Subscriber has received and carefully read the Seller's business
     plan and acknowledges that it has been furnished by the Seller during the
     course of this transaction with all information regarding the Seller that
     Subscriber requested or desired to know; that all documents which could be
     reasonably provided have been made available for the Subscriber's
     inspection and review; and that the Subscriber has been afforded the
     opportunity to ask questions of and receive answers from representatives of
     the Seller concerning the Seller and any additional information which the
     Subscriber has requested. The Subscriber acknowledges that any projections
     which it has been furnished do not constitute a representation or warranty
     as to the anticipated future financial performance of the Seller.

     B.  Such Subscriber understands that there is no public market for the
     Shares, and the Seller does not have any obligation or intention to
     register the Shares for sale under the Securities Act of 1933 as amended
     (the "Act") or any other securities laws.

     C.  Such Subscriber understands that (i) the Shares being purchased
     hereunder have not been registered under the Act or any other securities
     laws; (ii) the Subscriber cannot sell such Shares unless they are
     registered under the Act or any other applicable securities laws or unless
     exemptions from such registration requirements are available; (iii) a
     legend will be placed on any certificate or certificates evidencing the
     Shares stating that such Shares have not been registered under the Act and
     setting forth or referring to the restrictions on transferability and sales
     of the Shares; (iv) the Shares will be subject to significant transfer
     restrictions pursuant to the Stockholders' Agreement, by and among the
     Seller, the Subscriber and the other parties thereto (the "Stockholders'
     Agreement"); and (v) the Seller has no obligation to register the Shares or
     assist the Subscriber in obtaining an exemption from the various
     registration requirements except as set forth herein or therein. The
     Subscriber agrees not to resell the Shares without compliance with the
     terms of this Agreement, the Stockholders' Agreement, the Act and any and
     all applicable securities laws.

     D.  Such Subscriber (i) is acquiring the Shares solely for the Subscriber's
     own account for investment purposes only and not with a view toward resale
     or distribution, either in whole or in part; (ii) has no contract,
     undertaking, agreement or other arrangement, in existence or contemplated,
     to sell, pledge, assign or otherwise transfer the Shares to any other
     person; and has no present intention to enter into any such contract,
     undertaking agreement or arrangement; and (iii) agrees not to sell or
     otherwise transfer such Shares unless and until they are subsequently
     registered under the Act and any applicable securities laws or unless an
     exemption from any such registration is available.

     E.  Such Subscriber acknowledges that it has been informed that the
     Seller's business is highly speculative in nature; the Subscriber therefore
     understands that an investment in
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     the Shares involves substantial risks and the Subscriber recognizes and
     understands the risks relating to the purchase of the Shares; such
     Subscriber has such knowledge and experience in financial and business
     matters in general and in particular with respect to this type of
     investment that such Subscriber is capable of evaluating the merits and
     risks of an investment in the Shares.

     F.  Such Subscriber's investment in the Seller is reasonable in relation to
     its net worth and financial needs and such Subscriber is able to bear the
     economic risk of losing its entire investment in the Shares.

     G.  Such Subscriber represents that such Subscriber satisfies the
     definition of "accredited investor" as set forth in Rule 501(a) of
     Regulation D under the Act. A copy of this definition has been attached
     hereto under the heading "Investor Suitability Standards".

     H.  Such Subscriber understands that (i) the offering contemplated hereby
     has not been reviewed by any governmental body or agency; (ii) if required
     by the laws or regulations of any applicable jurisdiction, the offering
     contemplated hereby will be submitted to the appropriate authorities of
     such state(s) for registration or exemption therefrom; and (iii) the
     documents used in connection with this offering have not been reviewed or
     approved by any regulatory agency or government department, nor has any
     such agency or government department made any finding or determination as
     to the fairness of the Shares for investment.

     I.  Such Subscriber acknowledges that the Seller has the unconditional
     right to accept or reject this subscription, in whole or in part. The
     Seller will notify the Subscriber whether this subscription is accepted or
     rejected. If such subscription is rejected, payment will be returned
     without interest to the Subscriber.

     J.  If the undersigned is a natural person, the undersigned is 21 years of
     age or over. If the undersigned is a corporation, limited liability
     company, partnership, trust or other entity, the undersigned is authorized,
     empowered and qualified to execute this Agreement and to make an investment
     in the Seller as contemplated hereby. Each of this Agreement and the
     Stockholders' Agreement is valid, binding and enforceable against the
     undersigned in accordance with its terms. The undersigned is not aware of
     any laws or regulations that might be the basis for releasing the
     undersigned from the obligations created by this Agreement and the
     Stockholders' Agreement. This Agreement has been duly executed and
     constitutes the legal, valid and binding obligations of the Subscriber,
     enforceable in accordance with its terms.

     K.  If the Subscriber is purchasing the Shares in a fiduciary capacity for
     another person or entity, including without limitation a corporation,
     partnership, trust or any other entity, the Subscriber has been duly
     authorized and empowered to execute this Agreement and all other
     subscription documents, and such other person fulfills all the requirements
     for purchase of the Shares as such requirements are set forth herein,
     concurs in the purchase of the Shares and agrees to be bound by the
     obligations, representations, warranties and covenants contained herein.
     Upon request of the Seller, the Subscriber will provide true, complete and
     current copies of all relevant documents creating the Subscriber,

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     authorizing its investment in the Seller and/or evidencing the satisfaction
     of the foregoing.

     L.  No consent, approval or authorization of, or declaration or filing
     with, any governmental authority is required to be obtained or made by the
     Subscriber for the valid execution and delivery of this Agreement by the
     Subscriber or the valid purchase of Shares pursuant to this Agreement.

V.   Assignability. The Subscriber acknowledges that such Subscriber may not
     -------------
assign any of its rights to or interest in or under this Agreement without the
prior written consent of the Seller, and any attempted assignment without such
consent shall be void and without effect.

VI.  Representations and Warranties True. The representations and warranties set
     -----------------------------------
forth by the Subscriber above are true and correct as of the date hereof and
will be true and correct as of the date of the acceptance of this subscription
by the Seller in accordance with the terms of Section 4 hereof. If such
representations and warranties shall not be true and correct in any respect
prior thereto, the Subscriber will immediately give written notice of such fact
to the Seller, specifying which representations and warranties are not true and
correct and the reasons therefor.

VII. Indemnification. The Subscriber acknowledges that such Subscriber
     ---------------
understands the meaning and legal consequences of the representations and
warranties contained in Section 4 hereof, and the Subscriber hereby agrees to
indemnify and hold harmless the Seller, its officers or any of its affiliates,
salesmen, associates, agents or employees from and against any and all loss,
damage or liability (including costs and reasonable attorneys' fees) due to or
arising out of a breach of any representation, warranty or acknowledgment of the
undersigned contained in this Agreement or in the Subscriber Questionnaire which
is incorporated herein for all purposes.

VIII.Survival of Representations and Warranties. All representations and
     ------------------------------------------
warranties contained in this Agreement made in writing by the Subscriber
pursuant to this Agreement shall survive the execution and delivery of this
Agreement and the offer, sale and delivery of the Shares.

IX.  Notices. Any notice or other communication required or permitted hereunder
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shall be in writing and shall be delivered personally, sent by facsimile
transmission or sent by certified, registered or express mail, postage prepaid,
to the address of each party set forth herein. Any such notice shall be deemed
given when delivered personally, telegraphed, telexed or sent by facsimile
transmission (transmission confirmed) or, if mailed, five days after the date of
deposit in the United States mails.

X.   Miscellaneous.
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     A.  This Agreement shall be construed in accordance with and governed by
     the laws applicable to contracts made and wholly performed in New York
     (without giving effect to the conflict-of-law principles of another
     jurisdiction).

     B.  This Agreement may be executed in one or more counterparts, each of
     which shall be deemed an original but all of which together shall
     constitute one and the same instrument.
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     C.  This Agreement shall, except as otherwise provided herein, inure to the
     benefit of and be binding on the Seller and its successors and assigns and
     on the Subscriber and his or its respective heirs, executors,
     administrators, successors and assigns.

     D.  This Agreement, when accepted by the Seller, will constitute the entire
     agreement among the parties hereto with respect to the subject matter
     hereof and supersedes all prior and contemporaneous agreements and
     understandings, inducements or conditions, express or implied, oral or
     written, except as herein contained. This Agreement may not be modified,
     changed, waived or terminated other than by a writing executed by all the
     parties hereto. No course of conduct or dealing shall be construed to
     modify, amend or otherwise affect any of the provisions hereof.

     E.  When the context in which words are used in this Agreement indicates
     that such is the intent, singular words shall include the plural, and vice
     versa, and masculine words shall include the feminine and neuter genders,
     and vice versa.

     F.  Captions are inserted for convenience only, are not a part of this
     Agreement, and shall not be used in the interpretation of this Agreement.

     G.  In case any provision of this Agreement shall be invalid, illegal or
     unenforceable, such invalidity, illegality or unenforceability shall not in
     any way affect or impair any other provision of this Agreement.

XI.  CERTIFICATION. THE SUBSCRIBER CERTIFIES THAT SUCH SUBSCRIBER HAS READ THIS
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ENTIRE AGREEMENT AND THAT EVERY STATEMENT MADE BY THE SUBSCRIBER HEREIN IS TRUE
AND COMPLETE.
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                           SUBSCRIBER SIGNATURE PAGE
                           -------------------------

          THE UNDERSIGNED, desiring to subscribe for shares of Common Stock of
equip2move Corporation, a Delaware corporation, as is set forth below,
acknowledges that such Subscriber has received and understands the terms and
conditions of the Subscription Agreement attached hereto and that such
Subscriber does hereby agree to all the terms and conditions contained therein.

          IN WITNESS WHEREOF, the undersigned has hereby executed this
Subscription Agreement as of the date set forth below.

(PLEASE PRINT OR TYPE)

Number of shares to be purchased: 300,000

Per share Purchase Price: $0.25

Total Purchase Price: $75,000

(Number of shares multiplied by the price per share.)

Exact name(s) of Subscriber(s):                 SS# or Taxpayer ID#

                                            ____________________________
Signature of Subscriber(s):

By:  __________________________________________
     Name:
     Title:

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