Dokuchaev, M. A., & Kirichenko, V. V. (2002). Quasi-Frobenius Rings and Nakayama Permutations of Semiperfect Rings. Ukrains’kyi Matematychnyi Zhurnal, 54(7), 919-930. Retrieved from https://umj.imath.kiev.ua/index.php/umj/article/view/4128