Ed. Code, § 18138

With the consent of the county superintendent of schools the governing board of the school district may agree with the proper authorities of the county or city to terminate the affiliation of the district with the county or city library. Either the governing board of the school district or the governing body of the county library may initiate termination proceedings. The proceedings shall be terminated prior to the first day of February of the school year in which begun and may provide for either of the following:

(a) The complete withdrawal of affiliation effective on the first day of July next succeeding.

(b) A gradual withdrawal over a period of not to exceed three years beginning on the first day of July next succeeding the termination of proceedings.

The governing board of the school district shall enter into a written agreement with the proper authorities of the city or county providing for the terms of the gradual withdrawal, including the period to be covered, not to exceed three years, the amount of payment for each year, and the amount of service to be rendered.

Unless otherwise provided in the withdrawal agreement, the books purchased by a district during the period of the withdrawal become the property of the district.

All books purchased by a district shall be approved by the body authorized to adopt courses of study for the school districts of the county.