Nagia M. Ghanem Petri Net Models for Event Recognition in Surveillance Videos. 2007 University of Maryland, College Park, MD, USA https://hdl.handle.net/1903/6829 https://www.base-search.net/Record/f8f1b3adadf60554ec8f174fc833e331e4da149b1f6fb8fcf4a4c21f5399901e base-search.net (ftunivmaryland:oai:drum.lib.umd.edu:1903/6829)