Gottdiener, Mark, author
Westview Press, 2015
Buku Teks
Gilham, Oliver
Islan Press, 2002
Buku Teks
Flanagan, William G., author
Allyn and Bacon, 1990
Buku Teks
Bardo, John W.
F.E. Peacock Publishers, 1982
Buku Teks
Saltzstein, Alan L., author
Thompson, 2003
Buku Teks