TY  - BOOK
AU  - Smith, Sydney F
TI  - Telephony and telegraphy : an introduction to instruments and switching systems. (3rd ed.)
SN  - 0198593589
AV  - TK 6161 Smi 
PY  - 1978///
CY  - Oxford
PB  - Oxford University Press
KW  - TELEGRAPH
KW  - TELEPHONE
ER  -