Columbia subject headings:
Germany--History--1933-1945.
Great Britain--History--George VI, 1936-1952.
Imaginary histories.
World War, 1939-1945--Germany.
World War, 1939-1945--Great Britain.
Harvard subject headings:
Germany--History--1933-1945.
Great Britain--History--George VI, 1936-1952.
Imaginary histories
World War, 1939-1945--Germany.
World War, 1939-1945--Great Britain.
Princeton subject headings:
Operation Sea Lion.
World War, 1939-1945--Campaigns--Western Front.