V. T. Dinh, T. Q. Le, T. T. Do, N. P. Vu, and T. P. Thao Tran, “Single-Optimization of Ultrasonic Vibration-Assisted EDM for External Cylindrical Machining of 90CrSi”, Eng. Technol. Appl. Sci. Res., vol. 15, no. 4, pp. 25959–25970, Aug. 2025.