1. Some questions of phrase-structure grammars;Abraham;Comput. Linguist.,1965
2. Computing with membranes, Computing with Cells and Atoms;Calude,2000
3. Regulated Rewriting in Formal Language Theory;Dassow,1989
4. Nonterminal complexity of programmed grammars;Fernau,2001
5. Generalized P-systems with splicing and cutting/recombination;Freund;Grammars,1999