%0 Journal Article
%A Ya. N. Fel'd
%T A criterion for the realizability of direction diagrams by
%J Doklady Akademii Nauk
%D 1988
%P 583-587
%V 300
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1988_300_3_a15/
%G ru
%F DAN_1988_300_3_a15