Jacob Zimmermann Ludovic Mé Christophe Bidan An Improved Reference Flow Control Model for Policy-Based Intrusion Detection. 291-308 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=2808&spage=291 2003 conf/esorics/2003 ESORICS db/conf/esorics/esorics2003.html#ZimmermannMB03