%0 Journal Article
%A V. V. Lychagin
%T Geometric singularities of solutions of nonlinear differential equations
%J Doklady Akademii Nauk
%D 1981
%P 1299-1303
%V 261
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1981_261_6_a3/
%G ru
%F DAN_1981_261_6_a3