PARVINDER SINGH. Continuous and Contra Continuous Functions in Bi-topological Spaces. International Journal of Mathematics And its Applications, [S. l.], v. 3, n. 4 - E, p. 63–66, 2015. Disponível em: https://ijmaa.in/index.php/ijmaa/article/view/526. Acesso em: 22 jul. 2024.