Razi, A., S. A. Ab Shukor, and P. K. Shen. “Improved Harmonic Performance of Seven-Level CHB Inverter Using Multicarrier Modulation and Varying the Modulation Index”. Journal of Telecommunication, Electronic and Computer Engineering (JTEC), vol. 10, no. 1-7, Feb. 2018, pp. 53-57, https://jtec.utem.edu.my/jtec/article/view/3598.