Dennis Dams Rob Gerth Bart Knaack Ruurd Kuiper Partial-order Reduction Techniques for Real-time Model Checking. 469-482 1998 10 Formal Asp. Comput. 5-6 http://link.springer.de/link/service/journals/00165/bibs/8010005/80100469.htm db/journals/fac/fac10.html#DamsGKK98