Gianna Reggio Egidio Astesiano Christine Choppy Heinrich Hußmann Analysing UML Active Classes and Associated State Machines - A Lightweight Formal Approach. 127-146 2000 conf/fase/2000 FASE http://link.springer.de/link/service/series/0558/bibs/1783/17830127.htm db/conf/fase/fase2000.html#ReggioACH00