Clark, J. Desmond
The prehistory of Southern Africa
Penguin Books Inc., 1959
 Buku Teks
Problems in prehistory : North Africa and the Levant
edited by Fred Wendorf and Anthony E. Marks
SMU Press, 1975
 Buku Teks SO
Browne, G.S.
Europe Africa world population
F.W. Chesire, 1960
 Buku Teks
Africa in the modern world
edited by Calvin W. Stillman
University of Chicago Press, 1955
 Buku Teks SO
Emerging Africa in world affairs
compiled and edited by David K. Marvin
Chandler, 1965
 Buku Teks SO