Columbia subject headings:
Industries--Poland--History--20th century.
Poland--History--Occupation, 1939-1945.
Sabotage--Poland--History--20th century.
World War, 1939-1945--Underground movements--Poland.
Harvard subject headings:
Industries--Poland--History--20th century.
Poland--History--Occupation, 1939-1945
Sabotage--Poland--History--20th century.
World War, 1939-1945--Underground movements--Poland.
Princeton subject headings:
Poland--History--Occupation, 1939-1945.
World War, 1939-1945--Underground movements--Poland.