Harrigan, John J.
Little, Brown & Co., 1984
Buku Teks SO
Dye, Thomas R.
Prentice_Hall, Inc, 1988
Buku Teks SO
Saywell, John J.
University of Toronto Press , 1957
Buku Teks
Palumbo, Dennis J.
Harcourt Brace College, 1994
Buku Teks SO
Westview press 1985, 1982
Buku Teks SO