Freudenthal Suspension Theorem And James-Hopf Invariant of Spheres. Contemporary Mathematics , [S. l.], v. 3, n. 4, p. 514–524, 2022. DOI: 10.37256/cm.3420221857. Disponível em: https://ojs353.mebyme.cn/index.php/CM/article/view/1857. Acesso em: 24 dec. 2025.