Westview Press, 1980
Buku Teks
edited by Jacqueline A. Kalley, Elna Schoeman, Marlene Burger
University of South Africa, 2005
Buku Teks
edited by C. Grove Haines
John Hopkins Press, 1956
Buku Teks
Rouse, Irving
McGraw-Hill, 1972
Buku Teks
The American Society of African Culture, 1966
Buku Teks