%0 Journal Article %A M. Shirinbekov %T On approximation of superharmonic functions in open sets %J Sbornik. Mathematics %D 1987 %P 591-599 %V 57 %N 2 %I mathdoc %U http://geodesic.mathdoc.fr/item/SM_1987_57_2_a16/ %G en %F SM_1987_57_2_a16