Airmail Service 1934–1939", Zeppelin Study Group, Ickenham, UK 2000 ISBN 0-9514114-5-4 "Dornier H Falke". Germany. Archived from the original on 19 August...
Airmail Service 1934–1939, Zeppelin Study Group, Ickenham, UK. 2000. ISBN 0-9514114-5-4. Eden 2004, p. 442. Norris 1967, p. 3. Legg 2002, p. 285. Weathered...
Airmail Service 1934–1939", Zeppelin Study Group, Ickenham, UK 2000 ISBN 0-9514114-5-4 "First sustained jet airline service". Retrieved March 10, 2020. "Alitalia...