Christian Soe
McGraw-Hill, 2004
Buku Teks
Almond, Gabriel A.
Little, Brown & Co., 1978
Buku Teks
Wilson, Graham K.
Chatham House, 1985
Buku Teks
edited by Roy C. Macridis, Bernard E. Brown
Dorsey Press, 1968
Buku Teks
Barringron, Lowell
Wadsworth and Cengage Learning, 2013
Buku Teks