Okla. Stat. tit. 44, § 44-114: Accounts - Settlement

Settlement of Accounts. No bills or accounts shall be made by

any officer or enlisted man with a view of their being paid by the

State of Oklahoma unless such expenditure is expressly authorized by

the laws of this state or is authorized by the Adjutant General. No

accounts will be paid unless they are accompanied by vouchers or

receipts showing by whomever paid, or are to be paid, to whom paid,

date of service, authority for, and amount of such expenditure, and

for what purpose the expenditure was made.