1. Structure theory of Petri nets: the free choice hiatus;Best,1987
2. On liveness in extended non self-controlling nets;Barkaoui,1995
3. Regular marked Petri nets;Desel,1992
4. Free Choice Petri Nets;Desel,1995
5. M. Holk, Analysis of production schemata by Petri nets, TR-94, MIT, Project MAC, Boston 1972