TY  - JOUR
AU  - S. K. Voronina
TI  - A necessary condition for the system of eigen- and associated functions of an ordinary differential operator to be a basis in $L_2(0,1)$
JO  - Differencialʹnye uravneniâ
PY  - 1978
SP  - 407
EP  - 417
VL  - 14
IS  - 3
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1978_14_3_a1/
LA  - ru
ID  - DE_1978_14_3_a1
ER  -