WASET
    M. Zareiee and  A. Dideban,  Reducing the Number of Constraints in Non Safe Petri Net.   journal   = {International Journal of Electrical and Computer Engineering}, [online]. World Academy of Science, Engineering and Technology.
    January 2011, vol. 49(1). 20 - 23
    [viewed 26 April 2024]. Available from: https://publications.waset.org/pdf/11478.