Richman, Barry M.
Random House , 1969
Buku Teks
Basil Blackwell for the United Nations Industrial Development Organization, 1991
Buku Teks
Chang, John K.
Aldine, 1969
Buku Teks
Barnett, Arthur Doak
Frederick A. Praeger, 1962
Buku Teks
Lewis, John W.
Cornell University Press, 1963
Buku Teks