%0 Journal Article
%A N. A. Izobov
%T A refinement of the estimate in the freezing method for a two-dimensional system with coincident characteristic numbers
%J Differencialʹnye uravneniâ
%D 1971
%P 990-996
%V 7
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1971_7_6_a4/
%G ru
%F DE_1971_7_6_a4