definiens: means, with respect to the Product, the gross invoiced sales amount of the Product sold by WYETH or its Affiliates to non - affiliate Third Parties, after deduction of the following items, to the extent that such deductidns are reasonable and actually allowed, taken or incurred, and ( provided that such items do not exceed reasonable and customary amounts in the country in which the sale occurred ): ( a ) trade and quantity discounts, net of any give - backs received by WYETH in return ; ( b ) refunds, rebates, retroactive price adjustments, service allowances and broker 's or agent 's commissions ; ( c ) credits or allowances given for rejection or return of previously sold Product or for wastage replacement actually taken or allowed ; and ( d ) any tax, duties or government charge levied on the sale of Product and borne by WYETH and/or its Affiliates ( excluding national, state or local taxes based on income ) . Such amounts shall be determined from the books and records of WYETH and its Affiliates maintained in accordance with generally accepted accounting principles, consistently applied