Quah, Jon S. T., author
Emerald, 2010
Buku Teks
Quah, Jon S. T., author
Talisman Pub, 2010
Buku Teks
edited by Richard A. Chapman and A. Dunsire
George Allen and Unwin, 1971
Buku Teks
Simon, Herbert A., author
Alfred A. Knopf, 1973
Buku Teks
Buku Teks