%0 Journal Article
%A V. I. Fomin
%T Small perturbations of a singular differential equation with a constant unbounded operator coefficient
%J Differencialʹnye uravneniâ
%D 1989
%P 1629-1630
%V 25
%N 9
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1989_25_9_a27/
%G ru
%F DE_1989_25_9_a27