%0 Journal Article %A Per-Anders Ivert %T On Quasilinear Elliptic Systems of Diagonal Form. %J Mathematische Zeitschrift %D 1980 %P 283-286 %V 170 %I mathdoc %U http://geodesic.mathdoc.fr/item/MZ_1980__170_172918/ %F MZ_1980__170_172918