1. Context-free grammar forms;Cremers;J. Comput. System Sci.,1975
2. Some algebraic properties of k-bounded interpretation of grammar forms;Csuhaj-Varjú;Comput. Linguist. Comput. Languages,1981
3. A connection between descriptional complexity of context-free grammars and grammar form theory;Csuhaj-Varjú,1987
4. The Theory of Context-free Languages;Ginsburg,1966