[3]. Gh. Paun, Computing with membranes, J. Computer System Sciences,2000), in press, and TUCS Research Report No. 208, November, (http://www.tucs.fi), (1998).
[4]. Gh. Paun, Computing with membranes - A variant: P systems with polarized membranes, Intern. J. of Foundations of Computer Science,11, 1 (2000), 167-182, and CDMTCS Research Report No. 098, (ww.cs.auckland.ac.nz/CDMTCS), (1999).
[6]. Vasile Craciunean, A model of optimal aggregation of actions in manufacturing processes - ACADEMIC JOURNAL OF MANUFACTURING ENGINEERING, VOL. 12, ISSUE 4/2014, p. 30-35, (2014).
[8]. Vasile Craciunean, A Linguistic Model of Agregation in Virtual Manufacturing Processes - ACADEMIC JOURNAL OF MANUFACTURING ENGINEERING, VOL. 12, ISSUE 3/(2014).