GUO, Song-Tao. Heptavalent symmetric graphs of order 12p. Italian Journal of Pure and Applied Mathematics, [S. l.], v. 42, p. 161–172, 2019. Disponível em: https://journals.uniurb.it/index.php/ijpam/article/view/7250. Acesso em: 27 oct. 2026.