TY  - BOOK
T1  - The observer's book on radio navigation,
DA  - 1941.
CY  - Brooklyn, N. Y.,
AU  - Allan, Wilfred John Davy.
CN  - TL695
CN  - TL695
PB  - Chemical publishing co., inc.,
PP  - Brooklyn, N. Y.,
PY  - 1941.
ID  - 17896
KW  - Radio in aeronautics.
KW  - Navigation (Aeronautics)
TI  - The observer's book on radio navigation,
ER  -