@article{PM_2007_2007_1_a6,
     author = {Meziani, Rafik and Sad, Paulo},
     title = {Singularidades nilpotentes e integrales primeras.},
     journal = {Publicacions matem\`atiques},
     pages = {143-161},
     publisher = {mathdoc},
     volume = {51},
     number = {1},
     year = {2007},
     language = {fr},
     url = {http://geodesic.mathdoc.fr/item/PM_2007_2007_1_a6/}
}