TY  - BOOK
AU  - Biswas,Nripendra Nath
TI  - Principles of telephony
SN  - 021022312X
U1  - 621.385 
PY  - 1970///[Reprinted 1974]
CY  - New York, New Delhi
PB  - Asia Pub. House
KW  - Telephone, Automatic
N1  - Includes index
ER  -