TY  - GEN
AU  - Smith, Sydney F.
TI  - Telegphony and Telegraphy A: an introduction to intruments and exchnage (step-by-step and common control)
SN  - 0198593465
U1  - 621.385 
PY  - 1974///
CY  - London
PB  - Oxford University press
KW  - Telegraphy
KW  - Telephony
ER  -