Krievs, Oskars, Ingars Steiks, and Leonids Ribickis. “A PLL Scheme for Synchronization With Grid Voltage Phasor in Active Power Filter Systems”. Electrical, Control and Communication Engineering 27, no. 1 (January 1, 2010): 134–137. Accessed November 5, 2024. https://ecce-journals.rtu.lv/ecce/article/view/v10144-010-0035-x.