TY  - BOOK
AU  - Roddy, Dennis Coolen, John 
TI  - Electronic communications 
SN  - 81-203-0984-7 
U1  - 621.382 ROD  
PY  - 2000///
CY  - Prentice hall of india 
PB  - New Delhi 
KW  - COMMUNICATION SYSTEM
ER  -