PIWNIK, J. Komunikaty: Geometria Obszaru Uplastycznienia w Procesie Wyciskania. Engineering Transactions, [S. l.], v. 30, n. 1, p. 121–128, 1982. Disponível em: https://et.ippt.pan.pl/index.php/et/article/view/1971. Acesso em: 9 oct. 2025.