López, A., J. C. Cortés, J. R. García, and E. Castellanos. “MODELING FAULTS OF QUADCOPTER AERIAL VEHICLE USING PETRI NETS”. ITEGAM-JETIA, Vol. 5, no. 18, June 2019, pp. 81-88, http://br940.teste.website/~itegamjetia/journal/index.php/jetia/article/view/415.