TY  - BOOK
AU  - Carlson, Bruce, A Crilly, Paul, B 
TI  - Communication systems 
SN  - 0-07-121028-8 
U1  - 621.382 CAR  
PY  - 2000///
CY  - Tata Mcgraw hill 
PB  - Boston 
KW  - COMMUNICATION SYSTEM
ER  -