On open neighborhood energy of graphs. Gulf Journal of Mathematics, [S. l.], v. 15, n. 1, p. 119–130, 2023. DOI: 10.56947/gjom.v15i1.1122. Disponível em: https://gjom.org/index.php/gjom/article/view/1122. Acesso em: 18 sep. 2026.