Stanley, Timothy W., author
Westview Press, 1982
Buku Teks
Higgins, Benjamin
Richard D. Irwin, 1962
Buku Teks
edited by Coral Bell
Australian National University Press, 1980
Buku Teks
Buku Teks
edited by Robert W. Tucker, Charles B. Keely and Linda Wrigley
Westview Press, 1992
Buku Teks