Treaties, States Parties and Commentaries
Treaties and Documents
Geneva Conventions of 1949 and Additional Protocols, and their Commentaries
Historical Treaties and Documents
Rules concerning the Control of Wireless Telegraphy in Time of War and Air Warfare. Drafted by a Commission of Jurists at the Hague, December 1922 - February 1923.
Part II: Rules of Air Warfare#Chapter III: Belligerents. - Art. 14.
Art. 14. A military aircraft must be under the command of a person duly commissioned or matriculated military rolls of the State; the crew must be exclusively military.