Giovanni Chiola Claude Dutheillet Giuliana Franceschinis Serge Haddad A Symbolic Reachability Graph for Coloured Petri Nets. 39-65 1997 176 Theor. Comput. Sci. 1-2 db/journals/tcs/tcs176.html#ChiolaDFH97 http://dx.doi.org/10.1016/S0304-3975(96)00010-2