O. RAVI; I. RAJASEKARAN; S. MURUGESAN; A. PANDI. On $\beta$-normal Spaces. International Journal of Mathematics And its Applications, [S. l.], v. 3, n. 2, p. 35–44, 2015. Disponível em: http://ijmaa.in/index.php/ijmaa/article/view/418. Acesso em: 6 may. 2024.