P. T. A. Vu, N. V. Anh, N. D. Khang, and L. T. Q. Trang, “Model Order Reduction of a DC Motor System with a Buck Converter via a Gramians-Based Truncation Algorithm”, Eng. Technol. Appl. Sci. Res., vol. 15, no. 4, pp. 24417–24422, Aug. 2025.