1. The syntax and semantics of the proposed international language of the Zurich ACM-Gamm Conference;Backus,1959
2. Prolegomena to a theory of signal switching networks;Beizer,1962
3. A survey of Modern Algebra;Birkhoff,1954
4. Formulation of the problem;Carr,1968
5. First thoughts on grammatical inference;Feldman;Stanford Artificial Intelligence Memo No. 55,1967