S. Asgari and A. Haghany, “Rings whose nonsingular modules have projective covers”, Ukr. Mat. Zhurn., vol. 68, no. 1, pp. 3–13, Jan. 2016, Accessed: Dec. 05, 2025. [Online]. Available: https://umj.imath.kiev.ua/index.php/umj/article/view/1817