NOWEL, A.; SZAFRANIEC, Z. On trajectories of analytic gradient vector fields on analytic manifolds. Topological Methods in Nonlinear Analysis, [S. l.], v. 25, n. 1, p. 167–182, 2005. Disponível em: https://apcz.umk.pl/TMNA/article/view/TMNA.2005.008. Acesso em: 22 jul. 2024.