R. Freund, M. Kogler, S. Verlan:
"P Automata with controlled use of minimal Communication rules";
Talk: NCMA, Wroclaw; 2009-08-31 - 2009-09-01; in: "Workshop on Non-Classical Models for Automata and Applications", H. Bordihn, R. Freund, M Holzer et al. (ed.); Österreichische Computer Ges., Wien (2009), ISBN: 978-3-85403-256-4; 107 - 121.