Princeton University Press, 1980
Buku Teks
Cammack, Paul Anthony, author
Macmillan, 1993
Buku Teks
edited by Roy C. Macridis
Prentice-Hall, 1992
Buku Teks
Kegley, Charles W. (Charles William), Jr., author
Wadsworth, 2009
Buku Teks
Rourke, John T., author
Mc Graw Hill, 2009
Buku Teks