TY  - BOOK
AU  - Johnson,Charles D.
TI  - Communication systems
SN  - 0870069616
AV  - P90 .J56 1992
U1  - 302.2 20
PY  - 1992///
CY  - South Holland
PB  - Goodheart-Willcox
KW  - Communication
N1  - Includes index
ER  -