Michael J. Butler Carroll Morgan Action Systemes, Unbounded Nondeterminism, and Infinite Traces. 37-53 1995 7 Formal Aspects Comput. 1 db/journals/fac/fac7.html#ButlerM95 https://doi.org/10.1007/BF01214622 https://www.wikidata.org/entity/Q59626085