Essa, K., and P. Hartley. “Numerical Investigation on the Effect of Roller-Trace in Dual Pass Cup Spinning”. Advanced Technologies and Materials, vol. 34, no. 1-2, Dec. 2009, pp. 15-26, https://atm-journal.uns.ac.rs/index.php/atm/article/view/jtp.2009.34.1-2.2.