Limit cycles of cubic polynomial differential systems with rational first integrals of degree 2

摘要

Agraïments: FEDER-UNAB-10-4E-378, and a CAPES Grant No. 88881. 030454/2013-01 from the program CSF-PVE. The second authors is partially supported by the project CAPES Grant No. 88881.030454/2013-01 from the program CSF-PVE and CNPq grant “Projeto Universal 472796/2013-5”. The second author is supported by CAPES/GDU – 7500/13-0. The last author is supported by FAPESP-2010/17956-1.