GUO, Song-Tao. HEPTAVALENT SYMMETRIC GRAPHS OF ORDER 6p. Italian Journal of Pure and Applied Mathematics, [S. l.], v. 37, p. 741–750, 2017. Disponível em: https://journals.uniurb.it/index.php/ijpam/article/view/6758. Acesso em: 16 sep. 2026.