Vanishing holonomy and monodromy of certain centres and foci
Complex analytic methods in dynamical systems - IMPA, January 1992, Astérisque no. 222  (1994), p. 37-48
@incollection{AST_1994__222__37_0,
     author = {Brunella, Marco},
     title = {Vanishing holonomy and monodromy of certain centres and foci},
     booktitle = {Complex analytic methods in dynamical systems - IMPA, January 1992},
     editor = {Camacho C. and Lins Neto A. and Moussu R. and Sad P.},
     series = {Ast\'erisque},
     publisher = {Soci\'et\'e math\'ematique de France},
     number = {222},
     year = {1994},
     pages = {37-48},
     language = {en},
     url = {http://www.numdam.org/item/AST_1994__222__37_0}
}
Brunella, Marco. Vanishing holonomy and monodromy of certain centres and foci, in Complex analytic methods in dynamical systems - IMPA, January 1992, Astérisque, no. 222 (1994), pp. 37-48. http://www.numdam.org/item/AST_1994__222__37_0/

[C-M] D. Cerveau, R. Moussu: Groupes d'automorphismes de (𝐂,0) et équations différentielles ydy+=0, Bull. Soc. Math. France 116 (1988), 459-488.

[Mou1] R. Moussu: Une démonstration géométrique d'un théorème de Poincaré - Lyapunov, in Bifurcations, théorie ergodique et applications (Dijon), Astérisque 98-99 (1982), 216-223.

[Mou2] R. Moussu: Symétrie et forme normale des centres et foyers dégénérés, Erg. Th. and Dyn. Sys. 2 (1982), 241-251.

[Mou3] R. Moussu: Holonomie évanescente des équations différentielles dégénérées transverses, in Singularities and dynamical systems (ed. Pnevmatikos), Elsevier (1985), 161-173.

[M-R] J. Martinet, J.-P. Ramis: Analytic classification of resonant saddles and foci, in Singularities and dynamical systems (ed. Pnevmatikos), Elsevier (1985), 109-135.