Patricia Bouyer Pierre-Alain Reynier Serge Haddad Extended Timed Automata and Time Petri Nets. 91-100 2006 conf/acsd/2006 ACSD http://doi.ieeecomputersociety.org/10.1109/ACSD.2006.6 db/conf/acsd/acsd2006.html#BouyerRH06