Spero, Joan Edelman, author
Wadsworth, 2010
Buku Teks
Spero, Joan Edelman, author
Routledge , 1997
Buku Teks
Jackson, John H., author
West Publishing, 2013
Buku Teks
Rollason, Russell G.
Alternative Pub. Cooperative, 1981
Buku Teks
Gomes, Leonard
St. MArtin's Press, 1978
Buku Teks