TY  - BOOK
AU  - Smith,Sydney F.
TI  - Telephony and telegraphy / : an introduction to instruments and switching systems (electromechanical and reed-electronic) 
SN  - 0198593589 
U1  - 384.1 
PY  - 1978///
CY  - New York
PB  - Oxford University Press
KW  - Telephony engineering
ER  -