J. Ezpeleta, J. M. Colom and J. Martinez, “A Petri Net Based Deadlock Prevention Policy for Flexible Manufacturing Sys-tems,” IEEE Transactions on Robotics and Automation, Vol. 11, No. 2, April 1995, pp. 173-184. doi: 10.1109/70.370500
 Z. W. Li, J. Zhang and M. Zhao, “Li-veness-Enforcing Supervisor Design for a Class of Generalized Petri Net Models of Flexible Manufacturing Systems,” IEE Proceedings Control Theory & Applications, Vol. 1, No. 4, 2007, pp. 955-967. doi:10.1049/iet-cta:20060218
 C.-F. Zhong and Z.-W. Li, “Design of Liveness-Enforcing Supervisors via Transforming Plant Petri Net Models of FMS,” Asian Journal of Control (Special Issue on the Control of Discrete Event Systems), Vol. 6, No. 2, 2010, pp. 270-280.
 J. W. Guo and Z. W. Li, “A Deadlock Prevention Approach for a Class of Timed Petri Nets Using Elementary Siphons,” Asian Journal of Control, Vol. 12, No. 3, 2010, pp. 347-363. doi:10.1002/asjc.189
 M. Uzam and M. C. Zhou, “An Iterative Synthesis Approach to Petri Net Based Deadlock Pre-vention Policy for Flexible Manufacturing Systems,” IEEE Transactions on Systems, Man, and Cybernetics A, Vol. 37, No. 3, 2007, pp. 362-371. doi:10.1109/TSMCA.2007.893484
 L. Piroddi, R. Cor-done and I. Fumagalli, “Selective Siphon Control for Deadlock Prevention in Petri Nets,” IEEE Transactions on Systems, Man, and Cybernetics A, Vol. 38, No. 6, 2008, pp. 1337-1348. doi:10.1109/TSM CA.2008.2003535
 L. Piroddi, R. Cor-done and I. Fumagalli, “Combined Siphon and Marking Gen-eration for Deadlock Prevention in Petri Nets,” IEEE Transac-tions on Systems, Man, and Cybernetics A, Vol. 39, No. 3, May 2009, pp. 650-661. doi:10.1109/TSMCA.2009.2013189
 M. Uzam, Z. W. Li and M. C. Zhou, “Identification and Elimination of Redundant Control Places in Petri Net Based Liveness Enforcing Supervi-sors of FMS,” International Journal of Advanced Manufactur-ing Technology, Vol. 35, No. 1-2, 2007, pp. 150-168. doi:10.1007/s00170- 006-0701-5