T. HENSON; N. DEVI. On Direct Sum of Three Fuzzy Graphs. International Journal of Mathematics And its Applications, [S. l.], v. 6, n. 1 (Special Issue), p. 213–219, 2018. Disponível em: https://ijmaa.in/index.php/ijmaa/article/view/1415. Acesso em: 22 jul. 2024.