Holcombe, Arthur N.
Harvard University Press, 1940
Buku Teks
Sen, Krishna, author
Equinox, 2007
Buku Teks
Graber, Doris A., author
Congressional Quarterly Press, 1980
Buku Teks
Manzer, Ronald A., author
McGraw-Hill Ryerson, 1974
Buku Teks
McInnis, Edgar
Holt, Rinehart and Winston of Canada, 1982
Buku Teks