Cnp canada aviation sch 01.jpg
Originally scanned from: GWS - The Great War: The Standard History of the All Europe Conflict (volume four) edited by H. W. Wilson and J. A. Hammerton (Amalgamated Press, London 1915)

According to http://www.firstworldwar.com/photos/sources.htm, “Each photo is believed to be copyright-expired except where indicated.” The site has been up for seven years and sources for the photos cited so it is reasonable this claim of copyright expired status has stood the test of time.

Note: other than the source of the image and the assertion of copyright free status, detail information such as credits for each photographer and image provider was not indicated for each image.
en
Cnp canada aviation sch 01, Curtiss JN-4 (Can)
commons
en
Cnp canada aviation sch 01, Canadian aircraft., Canadian aircraft.
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ja
カナダ空軍のCnpカナダ航空CH01、カーチス JN-4(カナダ)
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ja
Cnpカナダ航空 sch01 - カナダの航空機。
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asserted