Columbia subject headings:
France--History--German occupation, 1940-1945.
World War, 1939-1945--Communications.
World War, 1939-1945--Military intelligence.
World War, 1939-1945--Underground movements--France.
Harvard subject headings:
France--History--German occupation, 1940-1945.
World War, 1939-1945--Communications.
World War, 1939-1945--Military intelligence.
World War, 1939-1945--Underground movements--France.
Princeton subject headings:
France--History--German occupation, 1940-1945.
World War, 1939-1945--Communications.
World War, 1939-1945--Military intelligence.
World War, 1939-1945--Underground movements--France.