WANG, A.; WANG, L. Congruences on regular semigroups with $Q$-inverse transversals. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 68, n. 6, p. 853–859, 2016. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/1884. Acesso em: 14 apr. 2025.