@article{PM_1997_1997_1_a7, author = {Delshams, Amadeu and Mir, Arnau}, title = {Series psi de campos vectoriales cuadr\'aticos en el plano.}, journal = {Publicacions matem\`atiques}, pages = {101-125}, publisher = {mathdoc}, volume = {41}, number = {1}, year = {1997}, language = {en}, url = {http://geodesic.mathdoc.fr/item/PM_1997_1997_1_a7/} }