SEMKO, N. N.; CHUPORDYA, V. A. On Schur classes for modules over group rings. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 59, n. 9, p. 1261–1268, 2007. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/3386. Acesso em: 6 dec. 2025.