Mo. Rev. Stat. § 100.140
At or before the issuance of the revenue bonds the governing body shall, by ordinance, create a sinking fund for the payment of the bonds and the interest thereon, and shall set aside and pledge a sufficient amount of the revenues of the project to be paid into the sinking fund at intervals to be determined by ordinance prior to the issuance of the bonds, for
(L. 1961 p. 189 § 14)