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:
"""
Modifications; Annexes; Miscellaneous 1) The laws of the Federal Republic of Germany shall apply to the Agreement and any legal relations thereof, especially any purchase order, between Cremer and Ultragenyx shall be governed by that law. The law of the United Nations Conventions of the formation of Agreements for the international sale of goods (CISG) is excluded. Exclusive place of Jurisdiction is Hamburg, Germany. 2) No addition or modification to this Agreement shall be valid unless made in writing and signed by the Parties. 3) The Annex attached to this Agreement form an integral part of the Agreement. 4) This Agreement, including the Annexes and any Statement of Work, constitutes the entire agreement between the Parties concerning the subject matter hereof and supersedes all written or oral prior agreements or understandings with respect thereto except the Confidentiality Agreement between the parties dated September 26t h, 2012. This Agreement shall be binding upon and shall inure to the benefit of the Parties hereto, their successors and assigns. 5) All waivers must be in writing and signed by the Party to be charged. Any waiver or failure to enforce any provision of this Agreement on one occasion will not be deemed a waiver of any other provision or of such provision on any other occasion. 6) Each Party must deliver all notices, consents, and approvals required or permitted under this Agreement in writing to the other Party at the address specified above, by personal delivery, by certified or registered mail (postage prepaid and return receipt requested), by a nationally- recognized overnight carrier, or by facsimile transmission with electronic confirmation of transmission. Notice will be effective upon receipt or refusal of delivery. Each Party may change its address for receipt of notice by giving notice of such change to the other Party. 7) This Agreement may be executed in counterparts by original signature, facsimile or PDF files, each of which shall be deemed an original, but all of which together shall constitute one and the same instrument. 5 Hamburg, November 19t h, 2012 /s/ Thomas Kassberg /s/ Dr. R. Stephan Ultragenyx Pharmaceutical Inc CREMER OLEO GmbH & Co KG CREMER OLEO GmbH & Co. KG Postfach 10 11 20, D-20007 Hamburg Tel: 040/320 11-0, Telefax 320 11-400 6 Annex A — Specification of the Product Trihepatanoin (Heptansäuretriglycerid) No Test EP method Limits 1 [***] [***], [***] 2 [***] [***] [***] 3 [***] [***] [***] 4 [***] [***] [***] 5 [***] [***] [***] 6 [***] [***] [***] 7 [***] [***] [***] 8 [***] [***] [***] 9 [***] [***] [***] 10 [***] [***] [***] 11 [***] [***] [***] 12 [***] [***] 13 [***] [***] [***] 18 [***] [***] [***] [***] Certain information in this document has been omitted and filed separately with the Securities and Exchange Commission. Confidential treatment has been requested with respect to the omitted portions. 7
"""

Extract the exact clause related to "Effective Date" from the excerpt above.

assistant: Not found.