Kovacs, Diane K.
Facet Publishing, 2007
Buku Referensi
Kern, M. Kathleen
American Management Association, 2009
eBooks
Cassell, Kay Ann
Neal-Schuman, an imprint of the American Library Association, 2013
Buku Teks SO
Rifni Raihana
Fakultas Ilmu Pengetahuan Budaya Universitas Indonesia, 2017
UI - Skripsi Open
edited by Bill Katz and Ruth A. Fraley
Haworth Press, 1984
Buku Referensi