In the absence of any other provision therefor, the management of the public library in any municipality, fire district or incorporated school district which has established such library under the provisions of section 11-20 shall be vested in a board of trustees, consisting of a number divisible by three to be elected in the manner provided in section 9-207. Such board may make bylaws for its government and shall have exclusive right to expend all money appropriated by such municipality for any such library.