%0 Journal Article %A Karátson, J. %T Gradient method in Sobolev spaces for nonlocal boundary-value problems %J Electronic Journal of Differential Equations %D 2000 %V 2000 %I mathdoc %U http://geodesic.mathdoc.fr/item/EJDE_2000__2000__a116/ %G en %F EJDE_2000__2000__a116