TY  - JOUR
AU  - Yu. K. Lando
TI  - Restrictions of an operator by orthogonality conditions imposed on its graph
JO  - Differencialʹnye uravneniâ
PY  - 1991
SP  - 717
EP  - 720
VL  - 27
IS  - 4
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DE_1991_27_4_a26/
LA  - ru
ID  - DE_1991_27_4_a26
ER  -