Mich. Comp. Laws § 397.405
All payrolls, bills, accounts and claims of every character against the library commission after having been duly audited and approved by the commission, the certificate of which audit and approval shall be endorsed thereon by the president or secretary of the commission or some member or other representative of the commission acting under authority conferred by the commission generally or specially, shall be transmitted to the city controller, who shall endorse thereon his approval or disapproval. When so endorsed with approval the controller shall draw his warrant or warrants on the city treasurer in payment therefor. No bill, account or claim shall be audited or approved by the commission unless the same shall be accompanied by a certificate of a representative of the commission who acted for the commission in making the purchase or contract or in taking the delivery or performance that he verily believes the services or property therein charged have been actually performed or delivered for the commission, that the sum or sums charged therefor are reasonable and just, and that to the best of his knowledge and belief no setoff exists, nor payment has been made on account thereof except such as are included or referred to in such account. A similar certificate shall be required upon all payrolls, the certificate to be made by the person under whose supervision the services charged have been rendered. The provisions hereof shall be in addition to any provisions covering the same matters in any general or local act or charter adopted pursuant to Act No. 279 of the Public Acts of 1909, as amended, being sections 117.1 to 117.38 of the Compiled Laws of 1948.
MCL 397.405