On Efficient Zero Ring Labeling and Restricted Zero Ring Graphs. European Journal of Pure and Applied Mathematics, Maryland, USA, v. 14, n. 1, p. 268–277, 2021. DOI: 10.29020/nybg.ejpam.v14i1.3890. Disponível em: https://www.ejpam.com/index.php/ejpam/article/view/3890. Acesso em: 23 nov. 2024.