TY  - BOOK
AU  - Bellamy, John, C 
TI  - Digital telephony 
SN  - 9-814-12635-7 
U1  - 621.385 7 BEL  
PY  - 2000///
CY  - John wiley & sons 
PB  - New York 
KW  - TELEPHONY
ER  -