@article {2189, title = {P systems with symport/antiport rules: When do the surroundings matter?}, journal = {Theoretical Computer Science}, volume = {805}, year = {2020}, pages = {206-217}, doi = {https://doi.org/10.1016/j.tcs.2018.04.052}, author = {David Orellana-Mart{\'\i}n and Miguel A. Mart{\'\i}nez-del-Amor and Luis Valencia-Cabrera and Bosheng Song and Linqiang Pan and Mario J. P{\'e}rez-Jim{\'e}nez} }