AsgariSh., and HaghanyA. “Rings Whose Nonsingular Modules Have Projective Covers”. Ukrains’kyi Matematychnyi Zhurnal 68, no. 1 (January 25, 2016): 3-13. Accessed November 27, 2024. https://umj.imath.kiev.ua/index.php/umj/article/view/1817.