%0 Journal Article
%A E. K. Ershov
%T The stability of the rotation number of a doubly periodic differential equation
%J Differencialʹnye uravneniâ
%D 1975
%P 1949-1955
%V 11
%N 11
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1975_11_11_a4/
%G ru
%F DE_1975_11_11_a4