Balaam, David N., 1950-, author
Prentice-Hall, 1996
Buku Teks
edited by W. Ladd Hollist
Westview Press, 1985
Buku Teks
McKeague, Charles P.
Academic Pres, 1982
Buku Teks
Hillner, Kenneth P.
Pergamon Press , 1978
Buku Teks
university of California Press, 1972
Buku Teks