GOTTLIEB, Daniel Henry. Topology and the non-existence of magnetic monopoles. CUBO, A Mathematical Journal, [S. l.], v. 2, n. 1, p. 99–117, 2000. Disponível em: https://cubo.ufro.cl/index.php/cubo/article/view/1767. Acesso em: 12 oct. 2025.