KEZLAN, T. P. ON COMMUTATIVITY THEOREMS FOR P. I. - RINGS WITH UNITY. Tamkang Journal of Mathematics, [S. l.], v. 24, n. 1, p. 29–36, 1993. DOI: 10.5556/j.tkjm.24.1993.4471. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4471. Acesso em: 2 may. 2024.