YOUSIF, Y. Y.; JASSIM, N. S. IJ--Perfect Functions Between Bitopological Spaces. Ibn AL-Haitham Journal For Pure and Applied Sciences, Baghdad, Iraq., v. 23, n. 2, p. 135–140, 2017. Disponível em: https://jih.uobaghdad.edu.iq/index.php/j/article/view/950.. Acesso em: 17 sep. 2024.