Gaya APA
ICAO, . (1951).
Circular 20 Identification of LF/MF Non Directional radio Beacons Utilizing Frequency Modulation .
Canada:
ICAO.
Gaya MLA
ICAO, .
"Circular 20 Identification of LF/MF Non Directional radio Beacons Utilizing Frequency Modulation".
Canada:
ICAO,
1951.
E-Book.