1. Non-context-free grammars generating context-free languages;Baker;Inform. Contr.,1974
2. On the structure of context-sensitive grammars;Book;Int. J. Computer Inform. Sci.,1973
3. The algebraic theory of context-free languages;Chomsky,1961
4. The relation between derivations and syntactical structures in phrase-structure grammars;Eickel;J. Computer Sys. Sci.,1972
5. The Theory and Application of Pushdown Store Machines;Evey,1963