25 C.F.R. § 36.40
(a) Each school shall provide a library/media program which shall, as a minimum, meet the applicable state and/or regional standards, but shall not be limited to these, and shall include the following:
(2) A written policy for the selection of materials and equipment shall be developed by a library committee in collaboration with the librarian and be approved by the school board. The collection of materials shall include as a minimum the following:
(i) A collection of books suitable for the range of student abilities and interests being served in the following ADM ratios.
(C) Secondary 9-12, 10 books per student
It is required that materials pertaining to Indian Tribes and/or Alaskan Natives be integrated within this basic collection.
(3) There shall be a library media center serviced by a librarian. Schools with fewer than 200 students are encouraged, wherever feasible, to cooperate in sharing librarian resources. Schools within an Agency and/or Area may cooperatively share the costs and services of a librarian who shall facilitate sharing of the combined available resources among the cooperating schools in accordance with the following ratios:
School Enrollment (ADM) Up to 100— 1/5 time librarian 101-200— 1/5 time librarian and 1/2 time library aide or 20 hours of library activity 201-400—1 full-time librarian or 2/5 time librarian provided the school has a full-time library aide 401 + —1 full-time librarian and a full-time library aide