Xiaoou Li 0001 Sergio V. Chapa Joselito Medina-Marín Jovita Martinez An application of conditional colored Petri nets: active database system. 4885-4890 2004 conf/smc/2004 SMC (5) https://doi.org/10.1109/ICSMC.2004.1401305 db/conf/smc/smc2004-5.html#LiCMM04