Davies, Ioan
Pall Mall Press, 1970
Buku Teks
The International Political Science Association, 2009
Buku Referensi
Ellsworth, John W
McGraw-Hill, 1976
Buku Teks
Marion, Jerry B.
John Wiley & Sons, 1979
Buku Teks
Toynbee, Arnold J.
Oxford University Press, 1966
Buku Teks