Dear Khorat,
I highly recommend the book,
Aerial Nationalism: A History of Aviation in Thailand, by Edward M. Young (who stayed many years in Thailand). This book eventhough written by Westerner but the most of the informatiom come mostly from Thai sources (some official ones) therefore it will give you more balanced and accurate information. The best part is Royal Thai air force during World War Two (fighting against the French, Japanese and allied). HTH.
tvidya