@article{ddd.uab.cat:221359,
      author = {Giné, Jaume and Llibre, Jaume},
       title = {Strongly formal weierstrass non-integrability for polynomial
               differential systems in C2},
     journal = {Electronic Journal of Qualitative Theory of Differential
               Equations},
        year = {2020},
      volume = {2020},
      number = {1},
       pages = {1--16},
    abstract = {Recently a criterion has been given for determining the weakly
               formal Weierstrass non-integrability of polynomial differential
               systems in C2. Here we extend this criterion for determining the
               strongly formal Weierstrass non-integrability which includes the
               weakly formal Weierstrass non-integrability of polynomial
               differential systems in C2. The criterion is based on the
               solutions of the form y = f(x) with f(x) ∈ C[[x]] of the
               differential system whose integrability we are studying. The
               results are applied to a differential system that contains the
               famous force-free Duffing and the Duffing-Van der Pol
               oscillators.},
         doi = {10.14232/ejqtde.2020.1.1},
         url = {https://ddd.uab.cat/record/221359},
}