“A New Multicarrier Sinusoidal Pulse Width Modulation (SPWM) Strategy Based on Rooted Tree Optimization (RTO) Algorithm for Reducing Total Harmonic Distortion (THD) of Switched-Capacitor Nine-Level Inverter in Grid-Connected PV Systems”. Indonesian Journal of Science and Technology, vol. 7, no. 1, Apr. 2022, pp. 19-36, https://doi.org/10.17509/ijost.v7i1.41716.