31 J. Campos José Merseguer S. Donatelli Thiagarajan 2006 On the integration of UML and Petri nets in software development Lecture Notes in Computer Science Springer-Verlag 4024 19-36 http%3A%2F%2Fwebdiis.unizar.es%2FCRPetri%2Fpapers%2Fjcampos%2F06_CM_LNCS.pdf