1. Alonso-González, C., Cano, F., Rosas, R.: Infinitesimal Poincaré-Bendixson problem in dimension three. ArXiv:1212.2134 [math.DS]
2. Alonso-González, C., Camacho, M.I., Cano, F.: Topological classification of multiple saddle connections. Discret. Contin. Dyn. Syst. 15, 395–414 (2006)
3. Alonso-González, C., Camacho, M.I., Cano, F.: Topological invariants for singularities of real vector fields in dimension three. Discret. Contin. Dyn. Syst. 20, 275–291 (2008)
4. Belotto, A.: Analytic varieties as limit periodic sets. ArXiv: 1109.0877v1 [math.DS]
5. Camacho, M.I.: A contribution to the topological classification of homogeneus vector fields. J. Differ. Equ. 57, 159–171 (1983)