GE, SHAN; LI, JIANGUO; XU, CHANGQING. Neighbor sum distinguishing total chromatic number of planar graphs without 4-cycles. Utilitas Mathematica , [S. l.], v. 105, 2017. Disponível em: https://utilitasmathematica.com/index.php/Index/article/view/1159. Acesso em: 1 may. 2026.