Button, John, author
Cassell, 1995
Buku Referensi
Schapiro, J. Salwyn, author
McGraw-Hill, 1950
Buku Teks
Achmad Jainuri, author
McGill University Montreal, 1992
Buku Teks
Woodham, Jonatham M., author
Oxford University Press, 1997
Buku Teks
edited by Jack A. Goldstone, Ted Robert Gurr, Farrokh Moshiri
Westview Press, 1991
Buku Teks