%0 Journal Article
%A A. Yanushauskas
%T A reduction of a directional derivative problem
%J Doklady Akademii Nauk
%D 1972
%P 1014-1017
%V 203
%N 5
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1972_203_5_a10/
%G ru
%F DAN_1972_203_5_a10