1. M. W. Alford, J. P. Ansart, G. Hommel, L. Lamport, B. Kiskov, G. P. Mullery, and F. B. Schneider,Distributed Systems, Lecture Notes in Computer Science, Vol. 190, Springer-Verlag, Berlin, 1985.
2. D. Angluin, Local and global properties in networks of processors,Proceedings of the 12th Symposium on The Theory of Computing, 1980, pp. 82?93.
3. C. Berge,Graphs and Hypergraphs, North-Holland, Amsterdam, 1977.
4. M. Billaud, P. Lafon, Y. Métivier, and E. Sopena,Graph Rewriting Systems with Priorities, Lecture Notes in Computer Science, Vol. 411, Springer-Verlag, Berlin, 1989, pp. 94?106.
5. B. Courcelle, Recognizable sets of unrooted trees, inTree Automata and Languages, M. Nivat and A. Podelski (editors), Elsevier, Amsterdam, 1992, pp. 141?157.