Buku Teks
Adelman, Irma
Stanford University Press, 1961
Buku Teks
Millikan, Max F.
Columbia University Press, 1967
Buku Teks
Bryce, Murray D.
The McGraw-Hill Book Company, 1960
Buku Teks
Hirschman, Albert O., editor
New York, N.Y. University Press, 1958
Buku Teks