TY  - BOOK
AU  - Hershberger,W.D.
TI  - Principles of communication systems
T2  - Prentice-Hall electrical engineering series
AV  - TK5101 .H43 1955
U1  - 621.38 
PY  - 1955///
CY  - New York
PB  - Prentice-Hall
KW  - Telecommunication
N1  - Includes index
ER  -