N.Muraly, P. Ajay-D-Vimal Raj. “Modular Multilevel Converters: A Review On Efficient Transformer Less Approach For Modeling And Control Schemes”. International Journal of Advanced Science and Technology, Vol. 29, no. 9s, May 2020, pp. 3444 -51, http://sersc.org/journals/index.php/IJAST/article/view/16286.