TY  - BOOK
AU  - Spangenberg, Karl R.
TI  - Vacuum tubes
PY  - 1948///
CY  - New York
PB  - McGraw-Hill Book Company, Inc.
UR  - http://krc.clri.res.in:80/cgi-bin/koha/opac-detail.pl?biblionumber=1563
ER  -