DANCHEV, Peter V. Weakly exchange rings whose units are sums of two idempotents. Вестник Санкт-Петербургского университета. Математика. Механика. Астрономия, [S. l.], v. 6, n. 2, p. 265–269, 2020. Disponível em: https://math-mech-astr-journal.spbu.ru/article/view/8417. Acesso em: 24 ноя. 2024.