1. Aho, A.V., Ulmann, J.D.: The Theory of Parsing, Translation, and Compiling, vol. 1. Prentice-Hall, Englewood Cliffs (1973)
2. Cienciala, L., Ciencialová, L., Csuhaj-Varjú, E.: Towards P colonies processing strings. In: Macías Ramos, L.F., Martínez Del Amor, M.A., Păun, G., Pérez Hurtado, I., Riscos Nuñez, A., Valencia Cabrera, L. (eds.) Twelfth Brainstorming Week on Membrane Computing, pp. 103–118. Fénix Editora (2014)
3. Cienciala, L., Ciencialová, L., Csuhaj-Varjú, E., Vaszil, G.: PCol automata: recognizing strings with P colonies. In: Martínez Del Amor, M.A., Păun, G., Pérez Hurtado, I., Riscos Nuñez, A. (eds.) Eighth Brainstorming Week on Membrane Computing, Sevilla, 1–5 February 2010, pp. 65–76. Fénix Editora (2010)
4. Cienciala, L., Ciencialová, L., Csuhaj-Varjú, E.: P colonies processing strings. Fundam. Inform. 134(1–2), 51–65 (2014)
5. Cienciala, L., Ciencialová, L., Csuhaj-Varjú, E.: A class of restricted P colonies with string environment. Nat. Comput. 15(4), 541–549 (2016)