%0 Journal Article %A Deng, Shengbing %A Yang, Jianfu %T Critical Neumann problem for nonlinear elliptic systems in exterior domains %J Electronic Journal of Differential Equations %D 2008 %V 2008 %I mathdoc %U http://geodesic.mathdoc.fr/item/EJDE_2008__2008__a98/ %G en %F EJDE_2008__2008__a98