This act shall apply to any joint city-county public libraries established and maintained under the provisions of Article X, Section 10A of the Oklahoma Constitution in any county having a population of one hundred thousand (100,000) or more according to the latest Federal Decennial Census, provided, that in counties with more than one hundred thousand (100,000) population, and having a metropolitan library system, such library may elect to come under the provisions of this act upon a majority vote of the city-county library commission.
Okla. Stat. tit. 65, § 552