Columbia subject headings:
Harvard subject headings:
Czechoslovakia--History--1938-1945.
Poland--History--Occupation, 1939-1945
World War, 1939-1945--Underground movements--Czechoslovakia.
World War, 1939-1945--Underground movements--Poland.
Princeton subject headings:
World War, 1939-1945--Underground movements--Czechoslovakia.
World War, 1939-1945--Underground movements--Poland.