TY  - BOOK
AU  - Biswas, N. N.
TI  - Principles Of Telephony
SN  - Nil
U1  - 384.6/B621p 
PY  - 1998///
CY  - New Delhi
PB  - UBS Publishers Distributors Ltd
KW  - Telephone
N1  - Department of Computer Science & Engineering
N2  - Telephone, Principle
ER  -