1. Theories of Abstract Automata;Arbio,1969
2. The Theory of Graphs;Berge,1964
3. On uniquely colorable planar graphs;Chartrand;J. Combin. Theory,1969
4. Minimally strong digraphs;Geller;Proc. Edinburgh Math. Soc.,1970
5. Realization with feedback encoding;Geller,1972