Hall, Peter
Blackwell, 2002
Buku Teks
edited by Jack A. Goldstone, Ted Robert Gurr, Farrokh Moshiri
Westview Press, 1991
Buku Teks
Black, C.E.
Alfred A. Knopf, 1961
Buku Teks
Varga, Eugen, 1879-1964
Foreign Languages Publishing House, 1961
Buku Teks
Kohn, Hans
D. Van Nostrand, 1965
Buku Teks