%0 Journal Article %A K. I. Babenko %T Some questions in the theory of extremal problems of univalent functions of class~$S$ %J Doklady Akademii Nauk %D 1970 %P 12-15 %V 194 %N 1 %I mathdoc %U http://geodesic.mathdoc.fr/item/DAN_1970_194_1_a1/ %G ru %F DAN_1970_194_1_a1