KRUHLYAK, S. A.; SAMOILENKO, Yu. S. Structure theorems for families of idempotents. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 50, n. 4, p. 523–533, 1998. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/4922. Acesso em: 5 dec. 2025.