1. Web grammars and several graphs;Abe;J. Comput. System Sci.,1973
2. Web Grammars and Their Application to Pattern Recognition;Brayer;Tech. Rep. Purdue Univ. TR-EE-1,1975
3. Data Structures and Graph Grammars;Della Vigna,1976
4. Using Graph Grammars to Define Sets of Digraphs;Furtado,1975