Rawlings, Philip, author
Longman, 1999
Buku Teks
Surette, Ray, author
Wadsworth and Cengage Learning, 2011
Buku Teks
Roth, Mitchel P., author
Cengage Learning , 2010
Buku Teks
Sheley, Joseph F., author
Wadsworth, 1987
Buku Teks
Arrigo, Bruce A., author
West/Wadsworth, 1999
Buku Teks