Sharkansky, Ira, author
McGraw-Hill, 1975
Buku Teks
Huntington, Samuel P., author
The Belknap Press, 1981
Buku Teks
edited by Stephen K. Bailey
United States Information Agency, 1973
Buku Teks
Singh, Robert
Polity Press, 2002
Buku Teks
[publisher not identified], 1968
Buku Teks