Modularization of biochemical networks based on classification of Petri net t-invariants. - Eva Grafahrend-Belau; Falk Schreiber; Monika Heiner; Andrea Sackmann; Björn H. Junker; Stefanie Grunwald; Astrid Speer; Katja Winder; Ina Koch (BMC Bioinform., 2008)