Christian Gloor Pascal Stucki Kai Nagel Hybrid Techniques for Pedestrian Simulations. 581-590 http://springerlink.metapress.com/openurl.asp?genre=article&issn=0302-9743&volume=3305&spage=581 2004 conf/acri/2004 ACRI db/conf/acri/acri2004.html#GloorSN04