Dokyun Na Inho Park Kwang Hyung Lee Doheon Lee Integration of Immune Models Using Petri Nets. 205-216 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3239&spage=205 2004 conf/icaris/2004 ICARIS db/conf/icaris/icaris2004.html#NaPLL04