TY  - GEN
AU  - Bates, Regis J.
TI  - Principles of Voice & Data Communications
SN  - 9780071257671 (pbk)
U1  - 621.38 
PY  - 2007///
CY  - Boston
PB  - Mc-Graw Hill, Publisher
KW  - Evolution of Telephone Set
N1  - Includes index
ER  -