@article{EJDE_2015__2015__a16,
     author = {Garrione,  Maurizio},
     title = {A note on a nonresonance condition at zero for first-order planar systems},
     journal = {Electronic journal of differential equations},
     year = {2015},
     volume = {2015},
     zbl = {1326.34070},
     language = {en},
     url = {http://geodesic.mathdoc.fr/item/EJDE_2015__2015__a16/}
}