Elcock, Howard, author
Longman, 1991
Buku Teks
Mitchell, Ferd H., author
CRC Press, 2016
Buku Teks
editors by Gisela M. von Dran; Jennifer Cargill
The Haworth Press, Inc., 1993
Buku Teks
Simon, Herbert A., author
Alfred A. Knopf, 1973
Buku Teks
Buku Teks