Columbia subject headings:
Harvard subject headings:
Germany--Foreign relations--Switzerland.
Switzerland--Foreign relations--Germany.
World War, 1939-1945--Aerial operations, German.
World War, 1939-1945--Diplomatic history.
Princeton subject headings:
Germany--Foreign relations--Switzerland.
Switzerland--Foreign relations--Germany.
World War, 1939-1945--Aerial operations, German.
World War, 1939-1945--Diplomatic history.