R. Freund, S. Ivanov et al.:
"How to Go Beyond Turing with P Automata: Time Travels, Regular Observer w-Languages, and Partial Adult Halting";
Talk: BWMC 2015, Sevilla; 2015-02-02 - 2015-02-06; in: "Proceedings of the Thirteenth Brainstorming Week on Membrane Computing", Gh. Paun et al. (ed.); Fenix Editora, (2015), 143 - 158.