Farrington, Karen, author
Chancellor Pres, 1998
Buku Referensi
Evans-Pritchard, E.E. (Edward Evan), 1902-1973, author
Clarendon Press, 1956
Buku Teks
Weber, Max, 1864-1920, author
Beacon Press , 1963
Buku Teks
Bender, David L., author
Grennhaven Press, 1981
Buku Teks
Johnstone, Ronald L., author
Prentice-Hall, 1975
Buku Teks