Narumi-Katayama and modified Narumi-Katayama indices of graphs. Journal of Prime Research in Mathematics, [S. l.], v. 13, n. 1, p. 08 – 15, 2017. Disponível em: https://jprm.sms.edu.pk/index.php/jprm/article/view/128. Acesso em: 7 dec. 2025.