Wei T. Yue Amitava Bagchi Tuning the Quality Parameters of a Firewall to Maximize Net Benefit. 321-329 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2918&spage=321 2003 conf/iwdc/2003 IWDC db/conf/iwdc/iwdc2003.html#YueB03