TY  - BOOK
AU  - Held,Gilbert
TI  - Understanding data communications: from fundamentals to networking 
SN  - 047196820X
PY  - 1996///
CY  - Chichester ; New York
PB  -  John Wiley & Sons
KW  - Data transmission systems
KW  - Computer networks
N1  - Includes index
ER  -