1. Balser, W.: Formal Power Series and Linear Systems of Meromorphic Ordinary Differential Equations, Springer-Verlag, (2000), New York
2. Balser, W.: From divergent power series to analytic function, Springer-Verlag, (1994), Berlin
3. Braaksma, B., Stolovitch, L.: Small divisors and Large Multipliers. Ann. Inst. Fourier Grenoble 57(2), 603–628 (2007)
4. Camacho, C.: On the local structure of conformal mappings and holomorphic vector fields in $$\mathbb{C}^2$$. Socité Mathématique de France, Astérisque 59–60, 83–94 (1978)
5. Camacho, C., Lins Neto, A., Sad, P.: Topological invariants and equidesingularization for holomorphic vector fields. J. of Diff. Geometry 20(1), 143–174 (1984)