%0 Journal Article
%A G. A. Los'
%T Theorems on the estimation of the invariant $A_1$ of the characteristic equation for an $n$th order linear homogeneous 

%J Differencialʹnye uravneniâ
%D 1970
%P 561-564
%V 6
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1970_6_3_a20/
%G ru
%F DE_1970_6_3_a20