Columbia subject headings:
Denmark--Foreign relations--Germany.
Germany--Foreign relations--Denmark.
Germany--Foreign relations--Sweden.
International relations.
Sweden--Foreign relations--Germany.
World War, 1939-1945.
Harvard subject headings:
Denmark--Foreign relations--Germany.
Germany--Foreign relations--Denmark.
Germany--Foreign relations--Sweden.
International relations
Sweden--Foreign relations--Germany.
World War, 1939-1945.
Princeton subject headings:
Denmark--Foreign relations--Germany.
Germany--Foreign relations--Denmark.
Germany--Foreign relations--Sweden.
International relations.
Sweden--Foreign relations--Germany.
World War, 1939-1945.