Lele, Uma
Johns Hopkins, 1975
Buku Teks
Chambers, Robert, 1932-
The Scandinavian Institute of African Studies, 1974
Buku Teks
Westview Press , 1990
Buku Teks
Cochrane, Glynn
Oxford University Press, 1971
Buku Teks
Selo Soemardjan
Cornell University , 1963
Buku Teks