Columbia subject headings:
Europe--History--1918-1945.
Germany--Foreign relations--1933-1945.
World War, 1939-1945--Underground movements--Europe.
Harvard subject headings:
Europe--History--1918-1945.
Germany--Foreign relations--1933-1945.
World War, 1939-1945--Underground movements--Europe.
Princeton subject headings:
World War, 1939-1945--Collaborationists--Europe.
World War, 1939-1945--Underground movements--Europe.