TY  - JOUR
AU  - Berg, I. D.
TI  - Index Theory for Perturbations of Direct Sums of Normal Operators and Weighted Shifts
JO  - Canadian journal of mathematics
PY  - 1978
SP  - 1152
EP  - 1165
VL  - 30
IS  - 6
UR  - http://geodesic.mathdoc.fr/articles/10.4153/CJM-1978-096-4/
DO  - 10.4153/CJM-1978-096-4
ID  - 10_4153_CJM_1978_096_4
ER  -