%0 Journal Article
%A V. G. Boltyanskii
%T Homotopical classification of vector fields
%J Doklady Akademii Nauk
%D 1958
%P 13-16
%V 118
%N 1
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1958_118_1_a1/
%G ru
%F DAN_1958_118_1_a1