Rosati, Jerel A., 1953-
Thomson, 2004
Buku Teks SO
Rosati, Jerel A., 1953-
Wadsworth, 2007
Buku Teks SO
Pratt, Julius W.
Prentice-Hall, 1965
Buku Teks SO
edited by Robert W. Tucker, Charles B. Keely, and Linda Wrigley
Westview Press, 1990
Buku Teks SO
Mangone, Gerard J.
Syracuse University Press, 1962
Buku Teks SO