The missing Japanese record of Singtao in 1939

What Japanese-language sources survive for Singtao in 1939?

Very few; much of the Japanese record was destroyed, and the surviving Chinese material is currently stronger.

Almost no Japanese-language material had been found for the episode despite an active search. Destruction of records leaves a major national perspective difficult to reconstruct. Chinese documentation has proved more plentiful, reversing what a researcher might initially expect. Archival survival can therefore shape the balance of evidence in diplomatic and naval history.