1. Some problems of finite representability;Altman;Information and Control,1965
2. Phrase Structure Languages, Finite Machines and Channel Capacity;Banerji;Information and Control,1963
3. Finite state languages;Chomsky;Information and Control,1958
4. The Algebraic Theory of Context-free Languages;Chomsky,1963
5. The Mathematical Theory of Context-free Languages;Ginsburg,1966