edited by Bill Katz and Ruth A. Fraley
Haworth Press, 1984
Buku Referensi
Cassell, Kay Ann
Neal-Schuman, an imprint of the American Library Association, 2013
Buku Teks SO
Kern, M. Kathleen
American Management Association, 2009
eBooks
Coffman, Steve
American Library association, 2003
eBooks
Liu, Jia
Chandos Publishing, 2007
Buku Teks SO