1. Z.H. Hu, X.H. Xu, D.Y. Sha, Skew Rolling and Cross-Wedge Rolling-Principles, Processes and Machines, Metal. Ind. Press, Beijing, China, (1985).
2. Zhang. Q. -S, A Study of Helical-Groove Rolling in China ,J. Mater. Process Technol. 21(1990)251-261.
3. Kenneth charles Skinner. Method and apparatus for producing rolled metal balls from bars or rods. United State patent. 3, 8378, 801. (1975).
4. Yang, S. -C.; Chen, C. -K. ,The surface geometry of rollers with skew rolling of steel balls. Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science , 215 ( 2001) 523-532.
5. Haibo. Yang. Modeling and Assessment of the Stress and Strain in the Skew Rolling Process by FEM, in Proceedings of the 7th CAE of Metal Plastic forming, Wuhan, Chian. 2002, pp.90-98.