O. El Hichami, M. Naoum, M. Al Achhab, I. Berrada, and B. E. El Mohajir, “An Algebraic Method for Analysing Control Flow of BPMN Models”, Int. J. Recent Contrib. Eng. Sci. IT, vol. 3, no. 3, pp. pp. 20–26, Oct. 2015.