Dokuchaev, M. A., and V. V. Kirichenko. “Quasi-Frobenius Rings and Nakayama Permutations of Semiperfect Rings”. Ukrains’kyi Matematychnyi Zhurnal 54, no. 7 (July 25, 2002): 919–930. Accessed December 6, 2025. https://umj.imath.kiev.ua/index.php/umj/article/view/4128.