ET. AL., Dr. D. Mrudula Devi. A characterization of Commutative Semigroups. Turkish Journal of Computer and Mathematics Education (TURCOMAT), [S. l.], v. 12, n. 3, p. 5150–5155, 2021. Disponível em: https://turcomat.org/index.php/turkbilmat/article/view/2065. Acesso em: 13 oct. 2025.