%0 Journal Article
%A S. K. Voronina
%T A necessary condition for the system of eigen- and associated functions of an ordinary differential operator to be a basis in $L_2(0,1)$
%J Differencialʹnye uravneniâ
%D 1978
%P 407-417
%V 14
%N 3
%I mathdoc
%U http://geodesic.mathdoc.fr/item/DE_1978_14_3_a1/
%G ru
%F DE_1978_14_3_a1