%0 Generic %D 2007 %T Active membrane systems without charges and using only symmetric elementary division characterise P %A Niall Murphy %A Damien Woods %E George Eleftherakis %E Petros Kefalas %E Gheorghe Paun %E Grzegorz Rozenberg %E Arto Salomaa %C Thessaloniki, Greece %I Springer %P 367-384 %S Membrane Computing %U http://www.cs.us.es/~dwoods/download/MurphyWoods-WMC07.pdf %V 4860 %Z Membrane Computing 8th International Workshop, WMC 2007 Thessaloniki, Greece, June 25-28, 2007 Revised Selected and Invited Papers %8 June 25-28