Protected Branches in Ordered Trees. Journal of Mathematical Study, [S. l.], v. 56, n. 1, p. 1–17, 2023. DOI: 10.4208/jms.v56n1.23.01. Disponível em: https://www.global-sci.com/index.php/jms/article/view/13436. Acesso em: 5 dec. 2025.