R. Freund, Gh. Paun, M. Pérez-Jiménez:
"Polarizationless P Systems with Active Membranes Working in the Minimally Parallel Mode";
Talk: UC2007, Kingston; 2007-08-13 - 2007-08-17; in: "Unconventional Computation", S. Akl, C. Calude et al. (ed.); LNCS, Springer, 4618 (2007), ISBN: 3-540-73553-4; 62 - 76.