Maity, K., S. Chaubey, and S. Rath. “A Numerical Analysis of Extrusion of Square Section from Round Billet through Mathematically Contoured Die With Design of Die Profile”. Advanced Technologies and Materials, vol. 38, no. 1, June 2013, pp. 75-83, https://jged.uns.ac.rs/index.php/atm/article/view/JTP.2013.38.1.7.