Ismail, R., D. M. Said, N. Ahmad, M. P. Abdullah, M. Y. Hassan, and A. O. Idris. “Optimization Method for Voltage Sag Monitor Placement in Power System”. International Journal of Electrical Engineering and Applied Sciences (IJEEAS), vol. 1, no. 1, Apr. 2018, pp. 71-80, https://ijeeas.utem.edu.my/ijeeas/article/view/3910.