Columbia subject headings:
Harvard subject headings:
Cryptography
United States. War Department. Military Intelligence Division. Section No. 8--History.
World War, 1914-1918--Military intelligence.
World War, 1914-1918--Secret service--United States.
Princeton subject headings:
Sino-Japanese War, 1937-1945--Personal narratives, American.
Sino-Japanese War, 1937-1945--Secret service--China.
Yardley, Herbert O. (Herbert Osborn), 1889-1958.