Newman, William H.
Prentice-Hall of Japan, 1963
Buku Teks
Brown, Wilfred
Heinemann, 1971
Buku Teks
Litterer, Joseph August, 1926-
John Wiley & Sons, 1973
Buku Teks
Roy, Robert H.
John Hopkins Press, 1958
Buku Teks
Jay M. Shafritz, J. Steven Ott, editor
Harcourt College, 2001
Buku Teks