Apter, David E., author
Winthrop, 1977
Buku Teks
Ebenstein, William, author
Thomson Wadsworth, 2002
Buku Teks
Evera, Stephen van, author
Cornell University Press, 1997
Buku Teks
Roucek, Joseph S., author
Thomas Y. Crowell Company, 1950
Buku Teks
The International Political Science Association, 2009
Buku Referensi