Selected papers that cite this one
Dennis F. Cudia. General
problems of formal grammars. Journal of the ACM,
17(1):31-43, January 1970.
David G. Cantor. On the
ambiguity problem of Backus systems. Journal of the
ACM, 9(4):477-479, October 1962.
Noam Chomsky. A note on
phrase structure grammars. Information and Control,
2(4):393-395, December 1959.