R. Freund, M. Ionescu, M. Oswald:
"Extended spiking neural P systems with decaying spikes and/or total spiking";
Talk: International Workshop Automata for Cellular and Molecular Computing, Budapest; 2007-08-31; in: "Proceedings of the International Workshop Automata for Cellular and Molecular Computing", Gy. Vaszil (ed.); MTA Sztaki, (2007), 64 - 75.