Tomiyuki Fukunaga Qi-Wei Ge Mitsuru Nakata On generating elementary T-invariants of Petri nets by linear programming. 168-171 2005 conf/iscas/2005 ISCAS (1) http://dx.doi.org/10.1109/ISCAS.2005.1464551 db/conf/iscas/iscas2005-1.html#FukunagaWN05