1. Beyond asymmetric choice: A note on some extensions;van der Aalst;Petri Net Newsletter,1998
2. Structure theory of Petri nets: The free choice hiatus;Best,1987
3. Some equivalence results for free choice nets and simple nets and on the periodicity of live free choice nets;Best,1983
4. Embedding as a tool for language comparison: On the CSP hierarchy;de Boer,1991
5. On the existence of symmetric algorithms to find leaders in networks of communicating sequential processes;Bougé;Acta Informatica,1988