Online - English translation, JAAF Official History volume for 12/41-6/42
 

https://library.oapen.org/bitstream/...=1&isAllowed=y

War History Series, Volume 5 (Extract) The Invasion of the South: Army Air Force Operations, and the Invasion of Northern and Central Sumatra Compiled by The War History Office of the National Defense College of Japan

this is an English translation of the JAAF official history. It covers just about all JAAF combat operations outside of China 12/41 - 6/42.