%0 Journal Article %A O. A. Oleinik %A E. V. Radkevich %T On~the analyticity of solutions of linear partial differential equations %J Sbornik. Mathematics %D 1973 %P 581-596 %V 19 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/SM_1973_19_4_a4/ %G en %F SM_1973_19_4_a4