Kruglуak S. A. Precise ideals of integer matrix rings of second order . Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 18, n. 3, p. 58–64, 1966. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/8737. Acesso em: 5 dec. 2025.