Inter-Parliamentary Union
Facts on File Publications, 1986
Buku Referensi
edited by Jon Pierre
Edward Elgar, 1994
Buku Teks
Duke University Press, 1979
Buku Teks
Palmer, Monte, author
Thomson, 2006
Buku Teks
Banfield, Edward C., author
Random House, 1967
Buku Teks