1. An undecidable problem about rational sets and contour words of polyominoes;Beauquier;Inform. Process. Lett.,1991
2. A decidability result about convex polyominoes;Beauquier,1991
3. Theory of Graphs and Applications;Berge,1962
4. Basic techniques for two-way finite automata;Birget,1989
5. Graph-theoretical properties and chain code picture languages;Dassow;J. Inform. Process. Cybernet.,1989