Marta Z. Kwiatkowska Gethin Norman David Parker Jeremy Sproston Performance analysis of probabilistic timed automata using digital clocks. 33-78 2006 29 Formal Methods in System Design 1 http://dx.doi.org/10.1007/s10703-006-0005-2 db/journals/fmsd/fmsd29.html#KwiatkowskaNPS06