Erzsébet Csuhaj-Varjú Antonio di Nola Gheorghe Paun Mario J. Pérez-Jiménez György Vaszil Editing Configurations of P Systems. 29-46 2008 82 Fundam. Inform. 1-2 http://iospress.metapress.com/content/ll73189q37090040/ db/journals/fuin/fuin82.html#Csuhaj-VarjuNPPV08