D. K. THAKKAR; V. R. DAVE. E-Colouring of a Graph. International Journal of Mathematics And its Applications, [S. l.], v. 4, n. 2 - A, p. 31–35, 2016. Disponível em: https://ijmaa.in/index.php/ijmaa/article/view/1002. Acesso em: 3 jul. 2024.