Dinh, V. T., 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”. Engineering, Technology & Applied Science Research, vol. 15, no. 4, Aug. 2025, pp. 25959-70, doi:10.48084/etasr.11450.