TY  - BOOK
AU  - Spangenberg, Karl R
AU  - Casmel, Ali Bulent (series editor)
TI  - Vacuum tubes
U1  - 621.381 512 SPA 
PY  - 1957///.
CY  - Reading : 
PB  - Addison - Wesley, 
KW  - Vacuum tubes
ER  -