A Lower Bound for the First Hyper-Zagreb Index of Trees with given Roman Domination Number. Journal of Prime Research in Mathematics, [S. l.], v. 21, n. 1, p. 49 – 54, 2025. Disponível em: https://jprm.sms.edu.pk/index.php/jprm/article/view/239. Acesso em: 19 sep. 2025.