Cavaliere, M., Freund R., Leistch A., & Paun G.  (2005).??Event-related outputs of computations in P systems.  (Miguel A. Gutiérrez-Naranjo, Agustín Riscos-Núñez, Francisco J. Romero-Campero, Dragos Sburlan, Ed.).Third Brainstorming Week on Membrane Computing.  107-122.