Hidayat, T., S. Tigor Franky D, and R. Mahardiko. “Energy Efficiency Analysis through Misalignment on New Design of Hexagonal Coil Array in Wireless Power Transfer”. International Journal of Integrated Engineering, vol. 12, no. 8, Aug. 2020, pp. 198-11, https://publisher.uthm.edu.my/ojs/index.php/ijie/article/view/5173.