%0 Journal Article
%A I. S. Kats
%T Some general theorems on the behaviour of spectral functions of second order differential systems
%J Doklady Akademii Nauk
%D 1958
%P 974-977
%V 122
%N 6
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DAN_1958_122_6_a4/
%G ru
%F DAN_1958_122_6_a4