Vilotić, Marko, Vesna Mandić, and Miroslav Plančak. 2004. “Ubet Analysis, Finite Element Simulation and Experimental Investigation of Backward Extrusion”. Advanced Technologies and Materials 29 (1-2):85-97. https://atm-journal.uns.ac.rs/index.php/atm/article/view/jtp.2004.29.1-2.9.