@article {1950, title = {Polarizationless P Systems with Active Membranes: Computational Complexity Aspects}, journal = {Journal of Automata, Languages and Combinatorics}, volume = {21}, year = {2016}, pages = {107{\textendash}123}, issn = {1430-189X}, author = {Luis Valencia-Cabrera and David Orellana-Mart{\'\i}n and Miguel A. Mart{\'\i}nez-del-Amor and Agust{\'\i}n Riscos-N{\'u}{\~n}ez and Mario J. P{\'e}rez-Jim{\'e}nez} }