The best source is Vincent Giordano who has travel extensively throughout Burma for the last 10 years or so, and is compiling a book on the bare knuckle fightiing arts of india, cambodia, thailand, bburma,and laos. He is a true source because he trained it and lived it. He has an email newsletter as well try him at
blackdiamondcobra@yahoo.com, he also has available to his members dvds he made of fights, and various events.