GAVRYLKIV, V.M. Superextensions of cyclic semigroups. Carpathian Mathematical Publications, [S. l.], v. 5, n. 1, p. 36–43, 2013. DOI: 10.15330/cmp.5.1.36-43. Disponível em: https://journals.pnu.edu.ua/index.php/cmp/article/view/3647. Acesso em: 6 may. 2024.