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 IV: Hostilities#Espionage. - Art. 28.
Art. 28. Acts of espionage committed, after leaving the aircraft, by members of the crew of an aircraft or by passengers transported by it, remain subject to the provisions of the Regulations concerning the laws and customs of war on land.