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.