Khaled El-Fakih Nina Yevtushenko Sergey Buffalov Gregor von Bochmann Progressive solutions to a parallel automata equation. 17-32 2006 362 Theor. Comput. Sci. 1-3 http://dx.doi.org/10.1016/j.tcs.2006.05.034 db/journals/tcs/tcs362.html#El-FakihYBB06