1. Syntax-directed recognition of hand-printed two-dimensional mathematics;Anderson,1968
2. On certain formal properties of grammars;Chomsky;Inform. Control.,1959
3. Perception, picture processing, and computers. II. “Machine Intelligence 1≓;Clowes,1967-1967
4. A generative picture grammar;Clowes,1967
5. On the formalization of handwriting;Eden,1961