JEYANTHI, P.; NALAYINI, P.; NOIRI, T. Pre-regular \(sp\)-open sets in topological spaces. CUBO, A Mathematical Journal, [S. l.], v. 20, n. 1, p. 31–39, 2018. DOI: 10.4067/S0719-06462018000100031. Disponível em: https://cubo.ufro.cl/index.php/cubo/article/view/1897. Acesso em: 12 oct. 2025.