%0 Journal Article %A Porreca, Antonio E. %A Mauri, Giancarlo %A Zandron, Claudio %T Complexity classes for membrane systems %J RAIRO - Theoretical Informatics and Applications - Informatique Théorique et Applications %D 2006 %P 141-162 %V 40 %N 2 %I EDP-Sciences %U http://www.numdam.org/articles/10.1051/ita:2006001/ %R 10.1051/ita:2006001 %G en %F ITA_2006__40_2_141_0