%0 Journal Article
%A N. S. Berezkina
%T Classes of third-order systems without moving critical points
%J Differencialʹnye uravneniâ
%D 1985
%P 517-520
%V 21
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1985_21_3_a18/
%G ru
%F DE_1985_21_3_a18