@article{EJDE_2002__2002__a44,
     author = {El Kahoui,  M'hammed},
     title = {On plane polynomial vector fields and the {Poincar\'e} problem},
     journal = {Electronic journal of differential equations},
     year = {2002},
     volume = {2002},
     zbl = {1068.34506},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2002__2002__a44/}
}