%0 Journal Article
%A V. S. Belonosov
%T Instability indices of differential operators
%J Sbornik. Mathematics
%D 1987
%P 507-525
%V 57
%N 2
%U http://geodesic.mathdoc.fr/item/SM_1987_57_2_a12/
%G en
%F SM_1987_57_2_a12