1. Adams, C. F. (1893). Sifting as a library policy. The Library journal, 18 (1), 118-119.
2. Biggs, M., & Biggs, V. (1987). Reference collection development in academic libraries. RQ, 27, 67-79.
3. Brough, K. J. (1953). Scolars workshop: evolving conceptions of library service. Urbana: University of Illinois.
4. Duncan Carter, M. (1974). Building library collection (4th ed.). Metuchen: The Scarecrow Press.
5. Claghorn Potter, A. (1934). The library of Harvard university. Boston: Harvard university.