TY  - BOOK
AU  - Spangenberg,Karl R.
TI  - Vacuum tubes
T2  - McGraw-Hill electrical and electronic engineering series
U1  - 621.384132 23
PY  - 1948///
CY  - New York
PB  - McGraw-Hill Book Co.
KW  - Vacuum-tubes
N1  - Include index
ER  -