1. On certain formal properties of grammars;Chomsky;Inform. Control,1959
2. Context-free grammars and pushdown storage;Chomsky,1962
3. Computability and Unsolvability;Davis,1958
4. Three theorems on phrase structure grammars of type 1;Landweber;Inform. Control,1963
5. Linear bounded automata;Myhill,1960