ABUJABAL, H. A. S.; KHAN, M. A.; SAMMAN, M. S. ON COMMUTATIVITY OF ONE-SIDED $s$-UNITAL RINGS. Tamkang Journal of Mathematics, [S. l.], v. 23, n. 3, p. 253–268, 1992. DOI: 10.5556/j.tkjm.23.1992.4549. Disponível em: https://journals.math.tku.edu.tw/index.php/TKJM/article/view/4549. Acesso em: 2 may. 2024.