TEAM, S. Between Preopen and Open Sets in Topological Spaces: Halgwrd M. Darwesh. Thai Journal of Mathematics, [S. l.], v. 11, n. 1, p. 143–155, 2013. Disponível em: https://thaijmath2.in.cmu.ac.th/index.php/thaijmath/article/view/365. Acesso em: 17 may. 2024.