H. F. Ahmed, H. Cha, A. A. Khan, J. Kim and J. Cho, "A Single-Phase Buck–Boost Matrix Converter With Only Six Switches and Without Commutation Problem," in IEEE Transactions on Power Electronics, vol. 32, no. 2, pp. 1232-1244, Feb. 2017, doi: 10.1109/TPEL.2016.2553044.