Simpson, D. B. (1975). The State Library Agencies: A survey report prepared for the Board of Directors of the Association of State Library Agencies and co-sponsored by the Chief Officers of State Library Agencies (2d ed.). Association of State Library Agencies.

Simpson, Donald Bruce. The State Library Agencies: A Survey Report Prepared for the Board of Directors of the Association of State Library Agencies and Co-sponsored by the Chief Officers of State Library Agencies. 2d ed. Chicago: Association of State Library Agencies, 1975.

Simpson, Donald Bruce. The State Library Agencies: A Survey Report Prepared for the Board of Directors of the Association of State Library Agencies and Co-sponsored by the Chief Officers of State Library Agencies. 2d ed. Association of State Library Agencies, 1975.