A cooperative board shall provide, directly or through a written contract, services to member libraries within the cooperative library's area. The services, subject to standards approved by the department in consultation with the state librarian, may include:

    (a) A central pool or rotating book collection.

    (b) In-service training.

    (c) Book selection aids.

    (d) Bibliographic services.

    (e) Audio-visual services.

    (f) Bookmobile service or other outlets to outlying areas.

    (g) Publicity and public relations.

    (h) Printing.

    (i) A centralized purchasing operation.

    (j) Centralized processing, including cataloging and marking.

    (k) Reference services.

    (l) Delivery service.