S. VENKATESAN; P. SEKAR. Exceptionality of Edge Graceful Labeling of Tricycle Graphs. International Journal of Mathematics And its Applications, [S. l.], v. 5, n. 4 - D, p. 535–539, 2017. Disponível em: https://ijmaa.in/index.php/ijmaa/article/view/1303. Acesso em: 22 jul. 2024.