Bach Quoc Khanh. “Optimal Placement of Dynamic Voltage Restorer – Solid State Fault Current Limiter Combination for Global Voltage Sag Mitigation in Distribution System”. The University of Danang - Journal of Science and Technology, vol. 17, no. 6, June 2019, pp. 44-49, https://jst-ud.vn/jst-ud/article/view/1880.