TY  - JOUR
AU  - Karl-Peter Hadeler
TI  - On the spectrum of normal operators and perturbations of them
JO  - Doklady Akademii Nauk
PY  - 1964
SP  - 1042
EP  - 1043
VL  - 158
IS  - 5
PB  - mathdoc
UR  - http://geodesic.mathdoc.fr/item/DAN_1964_158_5_a9/
LA  - ru
ID  - DAN_1964_158_5_a9
ER  -