1. Alhazov A., Martí n-Vide C., Pan L. (2003). Solving a PSPACE-complete problem by P systems with restricted active membranes. Fundam. Inf. 58(2):66–77
2. Alhazov A., Pan L. (2004). Polarizationless P systems with active membranes. Grammars 7(1):141–159
3. Alhazov A., Pan L., Păun Gh. (2004). Trading polarizations for labels in P systems with active membranes. Acta Inf. 41:111–144
4. Alhazov, A., Ishdorj, T.-O.: Membrane Operations in P Systems with Active Membranes. In: Păun, Gh., Riscos-Núñez, A., Romero-Jiménez, A., Sancho-Capparini, F. (eds.) Second Brainstorming Week on Membrane Computing, Sevilla, 2–7 February. Research Group in Natural Computing TR 01/2004, University of Sevilla, 37–44 (2004)
5. Burger K.N.J. (2000). Greasing membrane fusion and fission machineries. Traffic 1:605–613