Mo. Rev. Stat. § 143.143
143.143 Provisions of sections 143.131 and 143.141 effective, when.
143.143. Provisions of sections 143.131 and 143.141 effective, when. — The provisions of sections 143.131 to 143.143 shall apply with respect to all taxable years beginning after December 31, 1976.
(L. 1977 S.B. 451 § A)