A. Haque. Economics, Commerce and Trade Management: An International Journal (ECTIJ), volume 1 of IFIP Advances in Information and Communication Technology, page 15-25. https://airccse.com/ectij/papers/1117ectij02.pdf, (2017)
K. Hoffmann, H. Ehrig, and T. Mossakowski. 26th International Conference On Application and Theory of Petri Nets and Other Models of Concurrency, volume 3536 of Lecture Notes in Computer Science, Springer Verlag, London, (2005)
{. Genrich, and K. Lautenbach. Semantics of Concurrent Compilation, volume 70 of Lecture Notes in Computer Science, page 123--146. Springer-Verlag, Berlin, (1979)
C. Petri. Net theory and applications : Proceedings of the advanced course on general net theory,processes and systems (Hamburg, 1979), volume 84 of Lecture Notes in Computer Science, page 1--20. Springer-Verlag, Berlin, (1980)