This Agreement may be executed in several counterparts and by each party on a separate counterpart, each of which, when so executed and delivered, shall be an original, but all of which together shall constitute but one and the same instrument. In proving this Agreement, it shall not be necessary to produce or account for more than one such counterpart signed by the party against whom enforcement is sought. Delivery of an executed counterpart of a signature page to this Agreement by facsimile or electronic transmission shall be effective as delivery of a manually executed counterpart of this Agreement.