NAWAR , A. S.; ATALLAH, H. M. On \(\delta\beta\)-Open Sets in Tri Topological Spaces. Journal of Advanced Studies in Topology, [S. l.], v. 12, n. 1-2, p. 8–17, 2022. Disponível em: http://www.m-sciences.com/index.php/jast/article/view/284. Acesso em: 9 aug. 2022.