TUGANBAEV, A. A. Rings with projective basic right ideals . Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 42, n. 6, p. 861–863, 1990. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8855. Acesso em: 6 dec. 2025.