TY  - BOOK
AU  - Langley, Graham
AU  - Langley, GrahamRonayne, John
TI  - Telecommunications primer
SN  - 9780273601579
AV  - 621.382 LAN 1993 
U1  - 621.382 LAN 1993 
PY  - 1993///
CY  - London
PB  - Pitman Pub
KW  - Communication Engineering
ER  -