Hannah, H.W.
University of Illionois Press, 1966
Buku Teks
James, William E.
Asia Development Bank Economic, 1982
Buku Teks
Akhtar, Shahid
International Development Research Centre, 1975
Buku Teks
Gelfand, M.A.
Unesco, 1971
Buku Teks SO
Sommerlad, E.Lloyd
University Press, 1966
Buku Teks SO