%0 Journal Article
%A N. V. Medvedev
%T Some problems in the qualitative study of differential equations in the plane
%J Izvestiâ vysših učebnyh zavedenij. Matematika
%D 1961
%P 82-88
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/IVM_1961_6_a9/
%G ru
%F IVM_1961_6_a9