ASGARI, Sh.; HAGHANY, A. Rings whose nonsingular modules have projective covers. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 68, n. 1, p. 3–13, 2016. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1817. Acesso em: 5 dec. 2025.