TY  - JOUR
AU  - V. D. Budaev
TI  - A necessary condition for the Riesz basis property of systems of root functions of an ordinary nonselfadjoint differential operator
JO  - Differencialʹnye uravneniâ
PY  - 1993
SP  - 20
EP  - 29
VL  - 29
IS  - 1
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1993_29_1_a3/
LA  - ru
ID  - DE_1993_29_1_a3
ER  -