Columbia subject headings:
Germany--Foreign relations--Europe.
Neutrality--Europe--History--20th century.
World War, 1939-1945--Europe.
World War, 1939-1945--Germany.
Harvard subject headings:
Germany--Foreign relations--Europe.
Neutrality--Europe--History--20th century.
World War, 1939-1945--Europe.
World War, 1939-1945--Germany.
Princeton subject headings:
Germany--Foreign relations--Europe--1933-1945.
Neutrality--Europe--History--20th century.
World War, 1939-1945--Europe.
World War, 1939-1945--Germany.