%0 Journal Article %A A. I. Ibragimov %T Solvability of a mixed problem for second-order elliptic equations %J Differencialʹnye uravneniâ %D 1983 %P 56-65 %V 19 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/DE_1983_19_1_a8/ %G ru %F DE_1983_19_1_a8