system: You are a contract-analysis assistant performing a span-extraction task. You are given an excerpt from a commercial contract and the name of a clause type to locate within it.

Return the exact text of the requested clause, copied verbatim from the excerpt — identical wording and punctuation, with no paraphrasing, summarising, explanation, or added commentary.

The excerpt is one window of a much longer contract and often will not contain the requested clause. If the requested clause does not appear in this excerpt, respond with exactly: Not found.

Output only the extracted clause text, or the exact string `Not found.` — nothing else.

user: Contract excerpt:
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of energy sources including, inter alia, nuclear energy sources. SpinCo shall have the sole right to determine the content contained in future editions of the Steam Book, provided, however, that SpinCo will provide RemainCo with a right of first refusal to collaborate with SpinCo to provide content related to nuclear subject matter in the forty-third (43rd) edition of the Steam Book, with allocation of costs and revenues and any attribution and Copyright ownership with respect to RemainCo contributed content to be negotiated in good faith by the Parties. The foregoing right of first refusal shall cease in the event of a Change of Control of either RemainCo or SpinCo, provided, however, that the Parties will discuss the feasibility of future collaboration, specifically related to the contribution of nuclear related subject matter by RemainCo, in good faith in the event of a Change of Control. (d) RemainCo shall have, and SpinCo hereby grants to RemainCo, an unlimited, non-exclusive, perpetual, irrevocable, royalty free, worldwide right and license to use the content contained in the Steam Book, including the current edition and any past edition and any future edition to which RemainCo makes a contribution, for any purpose, including, without limitation, to reproduce, publicly display, modify, make derivative works, distribute, publicly perform and distribute for RemainCo's internal business purposes, including in connection with customer related activities, provided, however, that RemainCo shall (i) not use any non-nuclear content contained in the Steam Book in connection with publishing or distributing a publication which competes with the Steam Book and (ii) provide attribution and accreditation using a copyright notice having the format required by law in connection with the use of any protectable expression of the non-nuclear content contained in the Steam Book. SpinCo shall provide RemainCo with five hundred (500) copies of the current edition of the Steam Book at no cost to RemainCo, which copies RemainCo may distribute without limitation, including to RemainCo customers at no charge. In the event that RemainCo wishes to order additional copies of the current edition of the Steam Book or has a desire to purchase existing stock of earlier editions of the Steam Book, SpinCo will sell such copies to RemainCo at cost, which copies RemainCo may distribute without limitation, including to RemainCo customers at no charge. ARTICLE III TRADEMARKS Section 3.1 House Marks. (a) RemainCo agrees and acknowledges that (i) as of Distribution Date, as between the RemainCo Group and the SpinCo Group, all right, title and interest in and to the Trademarks set forth on Schedule 3.1 (the "SpinCo Trademarks"), including the SpinCo House Marks, shall be the sole and exclusive property of the SpinCo Group and (ii) except as otherwise provided in Section 3.2, the RemainCo Group shall cease and discontinue all use of the SpinCo Marks, including the SpinCo House Marks, as of the Distribution Date. In addition, RemainCo agrees to use its best efforts to change its name to eliminate Babcock & Wilcox therefrom, and, if applicable, to cause the members of the RemainCo Group to change their names to eliminate "Babcock," "Wilcox," "Babcock and Wilcox," "Babcock & Wilcox" or "B&W" therefrom and to cease and discontinue the use of the term "Babcock & Wilcox" or "B&W" and any of the 8 SpinCo Marks in its business or operations as promptly as practicable following the Distribution Date. Notwithstanding the foregoing, SpinCo agrees and acknowledges that RemainCo will change its name to BWX Technologies and that RemainCo and the RemainCo Group may continue to use "BW" and derivations thereof and therefrom (but not "B&W") in its business or operations after the Distribution Date. SpinCo agrees not to, and shall not permit any member of the SpinCo Group to, oppose, petition to cancel, or otherwise challenge or object to the use of or any current application and/or subsequent application for registration by RemainCo or any member of the RemainCo Group of any RemainCo House Marks as long as such use and/or registration does not make use of the SpinCo House Marks and further agrees to take such actions as may be reasonably requested by RemainCo and execute or cause to be executed by the appropriate members of the SpinCo Group such other agreements, instruments and other documents, including coexistence agreements and letters of consent, as may be reasonably requested by RemainCo to facilitate the registration and continued prosecution of RemainCo House Marks (e.g., in the event that any SpinCo House Mark is cited against an application for a RemainCo House Mark). (b) RemainCo agrees not
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Extract the exact clause related to "Price Restrictions" from the excerpt above.