%0 Journal Article %A Marcos do Ó, João %A Ubilla, Pedro %T A multiplicity result for a class of superquadratic Hamiltonian systems %J Electronic Journal of Differential Equations %D 2003 %V 2003 %I mathdoc %U http://geodesic.mathdoc.fr/item/EJDE_2003__2003__a150/ %G en %F EJDE_2003__2003__a150