%0 Journal Article %A V. V. Katrakhov %T General boundary value problems for a~class of singular and degenerate elliptic equations %J Sbornik. Mathematics %D 1981 %P 325-347 %V 40 %N 3 %I mathdoc %U http://geodesic.mathdoc.fr/item/SM_1981_40_3_a2/ %G en %F SM_1981_40_3_a2