233.30  School board cooperative libraries.--Each school board may, at its discretion, make contracts or agreements with county or community groups or organizations for a cooperative program or programs of library establishment, maintenance, and use, and all such contracts or agreements with county or community groups or organizations shall provide that such cooperative school and county or school and community libraries shall be established on public school property and shall continue under the supervision and control of such school board; and such part of the costs therefor as may, by contract or agreement, be properly chargeable to such school board shall be defrayed out of available district general school funds or, under limitations prescribed by law, other funds which may be or may become available for such purposes.