BABU, D. Reddy; VARMA, P.L.N. AVERAGE D-DISTANCE BETWEEN VERTICES OF A GRAPH. Italian Journal of Pure and Applied Mathematics, [S. l.], v. 33, p. 293–298, 2014. Disponível em: https://journals.uniurb.it/index.php/ijpam/article/view/6253. Acesso em: 7 aug. 2026.