Maoan Han. The Hopf cyclicity of Lienard systems. Appl. Math. Lett., 14(2):183-188, 2001. [doi]
@article{Han01:1, title = {The Hopf cyclicity of Lienard systems}, author = {Maoan Han}, year = {2001}, doi = {10.1016/S0893-9659(00)00133-6}, url = {http://dx.doi.org/10.1016/S0893-9659(00)00133-6}, researchr = {https://researchr.org/publication/Han01%3A1}, cites = {0}, citedby = {0}, journal = {Appl. Math. Lett.}, volume = {14}, number = {2}, pages = {183-188}, }