On The Closed Geodesics Problem. São Paulo Journal of Mathematical Sciences, [S. l.], v. 2, n. 2, p. 223–237, 2008. DOI: 10.11606/issn.2316-9028.v2i2p223-237. Disponível em: https://revistas.usp.br/spjournal/article/view/29.. Acesso em: 27 abr. 2024.