LLIBRE, Jaume. Periods of self-maps on $\rm S^2$ via their homology. Ukrains’kyi Matematychnyi Zhurnal, [S. l.], v. 76, n. 1, p. 72–74, 2024. DOI: 10.3842/umzh.v76i1.7668. Disponível em: https://umj.imath.kiev.ua/index.php/umj/article/view/7668. Acesso em: 5 apr. 2025.