Gaultney, Jane F., author
California, 2007
Buku Teks
Schick, Theodore
McGraw-Hill , 1998
Buku Teks
edited by Cath Sulivan and Michael A. Forrester
Sage, 2019
Buku Teks
Leach, John, 1953-
Philadelphia Open University Press 1991,
Buku Teks
Bell, Phillip, author
Sage, 2001
Buku Teks