محمد زكي شيت الصفار ل. On MP–rings and DS–ringsLugen .M.Zake.Sheet Al-Sufar. College of Basic Education Research Journal, [S. l.], v. 5, n. 3, p. 243–253, 2007. DOI: 10.33899/berj.2007.Vol5.Iss3.39226. Disponível em: https://berj.uomosul.edu.iq/index.php/berj/article/view/39226. Acesso em: 4 nov. 2025.