%0 Journal Article %A V. S. Vinogradov %T Investigation of boundary value problems for elliptic systems of first order %J Matematičeskie zametki %D 1973 %P 291-304 %V 14 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/MZM_1973_14_2_a14/ %G ru %F MZM_1973_14_2_a14