5S. G. Amin, M. H. M. Ahmed, H. A. Youssef.Computer-aided design of acoustic horns for ultrasonic machining using finite-element anslysis. Journal of Materials Processing Technology, 1995 : 254-260.
6T. B. Thoe, D. K. Aspinwall, M. L. H. Wise. Review on ultrasonic machining International. Journal of Machine Tools and Manufacture, 1998,38(4):239-255.