edited by Michael M. Horowitz and Thomas M. Painter
Westview Press, 1986
Buku Teks
Lele, Uma
Johns Hopkins, 1975
Buku Teks
Chambers, Robert, 1932-, author
The Scandinavian Institute of African Studies, 1974
Buku Teks
Westview Press , 1990
Buku Teks
Cochrane, Glynn, author
Oxford University Press, 1971
Buku Teks