@article {, title = {Computational Complexity in P Systems}, journal = {Workshop on Membrane Computing, WMC5}, year = {2004}, month = {June 14-16}, pages = {63}, address = {Mil{\'a}n, Italia}, attachments = {http://cantor.cs.us.es/files/Computational Complexity in P Systems.pdf}, author = {Mario J. P{\'e}rez-Jim{\'e}nez}, editor = {Giancarlo Mauri and Gheorghe Paun and Claudio Zandron} }