TY  - BOOK
AU  - Biswas, Nripendra, N 
TI  - Principles if telephony 
SN  - 81-85273-09-X 
U1  - 621.3857 BIS  
PY  - 1998///
CY  - Radiant books 
PB  - Bangalore 
KW  - TELEPHONY
ER  -