TY  - BOOK
AU  - Friedrichs K O
TI  - Spectral theory of operators in Hilbert spaces
U1  - 515.733 
PY  - 1974///
CY  - London
PB  - George Allen & Unwin
KW  - Calculus
KW  - Hilbert spaces
KW  - Spectral theroy
ER  -