1. Unpublished effort by Aeroprojects Inc, West Chester, Pennsylvania, USA
2. Production tube drawing of metals using ultrasonic energy applied to the mandrel;Clauser,1966
3. Ultrasonic process speeds tube drawing;Steel,1966
4. The fundamentals of wire drawing;Wistreich;Metallurgical Reviews,1958
5. Ultrasonics reduces “stick-slip” action;The Machinist,1953