The Contractor shall check all material and labor entering into the work and shall keep such full and detailed accounts as may be necessary to proper financial management under this Agreement and the system shall be such as is satisfactory to the Architect or to an auditor appointed by the Owner. The Architect, the auditor and their timekeepers and clerks shall be afforded access to the work and to all the Contractor's books, records, correspondence, instructions, drawings, receipts, vouchers, memoranda, etc., relating to this contract, and the Contractor shall preserve all such records for a period of two years after the final payment hereunder.