Alazemi, Saud, Irfan Hilmy, and Erry Adesta. “Indentation Mechanism in Rotary Hammer Forging Process: Analytical and Numerical Approach”. International Journal of Engineering Materials and Manufacture 3, no. 4 (December 1, 2018): 190-199. Accessed April 18, 2019. http://deerhillpublishing.com/index.php/ijemm/article/view/78.