TY  - BOOK
AU  - Lehnert, Joseph 
TI  - Introduction to telegraph engineering
SN  - 3-8009-1189-2
U1  - 621.382 
PY  - 1969///
CY  - London
PB  - Hyden & Son
KW  - Communication engineering
KW  - Telecommunication
N1  - Includes index
ER  -