Cady, John F.
American Institute of Pacific Relations, 1948
Buku Teks
Furnivall, JS
Solidaridad publishing house, 1974
Buku Teks
Hayder, Joseph Ralston
Macmillan, 1950
Buku Teks
Bello, Walden F., author
Institute for Food and Development Policy, 1982
Buku Teks
Macmillan, W.M., author
Faber and Faber, 1959
Buku Teks