3David A. Tyckoson. What Is The Best Model of Reference Service?.Library Trends, Fall 2001,50(2): 183-197.
4Rieh, Soo Young. Changing Reference Service Environment: A Review of Perspectives from Managers, Librarians, and Users. Journal of Academic Librarianship, May 99,25(3): 178-187.
5Constance Miller, James Rettig. Reference Obsolescence, RQ25(1985):52-58.
6Ferguson, Bunge. The Shape of Services:254.
7Joan C. Durrance. Factors That Influence Reference Success: What Makes Questioners Willing to Return?. The Reference Librarian, 1995(49/50):243-265.
8Whitson. Differentiated Service: 103-110.
9Association of Research Libraries. Information Desks in Libraries(SpecKit 172). Washington D.C.:Association of Research Libraries, 1991.
