TY  - BOOK
AU  - Macpherson,Sandra
TI  - What are vads ? a guide to value added and data services
SN  - 085012669X
U1  - TK/5105 
PY  - 1987///
CY  - Oxford Road, Manchester ,Engla
PB  - NCC
KW  - Telecommunication systems.
ER  -