TY  - BOOK
AU  - Friedrichs K O
TI  - Perturbation of spectra in Hilbert space
U1  - 530.1 
PY  - 1965///
CY  - Providence
PB  - AMS
KW  - Hilbert space
KW  - Physics
KW  - Spectra
N1  - Proc. of the Summer Seminar, Boulder, Colorado, 1960
ER  -