TY  - GEN
AU  - Smith Sydney F
TI  - Telephony & telegraphy A : : an introduction to telephone and telegraph instruments and exchanges 
AV  - TK6161  
U1  - 621.38 
PY  - 1969///
CY  - London
PB  - Oxford U.P., 
KW  - Telephone
KW  - Telegraph
N1  - Includes bibliographical references
ER  -