On Double Roman Dominating Functions in Graphs. European Journal of Pure and Applied Mathematics, Maryland, USA, v. 16, n. 2, p. 847–863, 2023. DOI: 10.29020/nybg.ejpam.v16i2.4653. Disponível em: https://ejpam.com/index.php/ejpam/article/view/4653.. Acesso em: 3 jul. 2024.