Styan, J.L., author
Cambridge University Pres, 1977
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
Black, C.E., author
Alfred A. Knopf, 1961
Buku Teks
Varga, Eugen, 1879-1964, author
Foreign Languages Publishing House, 1961
Buku Teks