%0 Journal Article %A L. V. Ovsyannikov %T Singular operator in the scale of Banach spaces %J Doklady Akademii Nauk %D 1965 %P 819-822 %V 163 %N 4 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1965_163_4_a8/ %G ru %F DAN_1965_163_4_a8