1. Petri nets and commutative grammars;Crespi-Reghizzi;Rapp. 74-75,1974
2. A decidability theorem for a class of vector-addition systems;Crespi-Reghizzi;Inform. Process. Letters,1975
3. Proper termination of flow-of-control in programs involving concurrent processes;Gostelow,1972
4. Analysis of production schemata by Petri nets;Hack;M.I.T.-Project MAC,1972
5. Extended state-machine-allocatable nets (ESMA), an extension of free choice Petri net results;Hack;Computation Structures Group Memo,1973