Dr. Ziad Shakeeb Al Sarraf, Dr. Ahmed Fattah Ahmed and Mr. Khalid Alias Hammo (trans.) (2023) “Evaluation of Vibration Amplitude Stepping and Welding Performance of 20 kHz and 40 kHz Ultrasonic Power of Metal Welding”, Indian Journal of Production and Thermal Engineering (IJPTE), 1(2), pp. 11–15. doi:10.54105/ijpte.B2009.061221.