AFZAL, HAFIZ USMAN; ASLAM, MUHAMMAD. On the deficiency of disjoint union of further planar classes of graphs. Utilitas Mathematica , [S. l.], v. 105, 2017. Disponível em: https://utilitasmathematica.com/index.php/Index/article/view/1158. Acesso em: 19 jun. 2026.