Charles Letts' Self-Opening Diary for 1936, labelled "(Si T'ep eh)", entries January-March, some notes and lists at back of diary. The diary covers Wales' excavation in [possibly Sri thep, Pejabun , Thailand] and time in Bangkok.

The Papers of Horace Geoffrey Quaritch Wales contain papers relating to his archaeological work in southeast Asia including expedition notes, personal notebooks, diaries, manuscript proofs, correspondence, newspaper cuttings and maps. Listed within this catalogue are objects and items of furniture which were also part of the bequest of Quaritch Wales' wife, Dorothy, to the Royal Asiatic Society.