GERMINARIO, A.; GIANNONI, F. Morse theory for Riemannian geodesics without nondegeneracy assumptions. Topological Methods in Nonlinear Analysis, [S. l.], v. 10, n. 2, p. 295–325, 1997. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.1997.034. Acesso em: 23 apr. 2024.