Columbia subject headings:
Limburg (Belgium : Province)--History.
World War, 1939-1945--Underground movements--Belgium--Limburg (Province)
Harvard subject headings:
Limburg (Belgium : Province)--History.
World War, 1939-1945--Underground movements--Belgium--Limburg (Province)
Princeton subject headings:
Limburg (Belgium : Province)--History.
World War, 1939-1945--Underground movements--Belgium--Limburg (Province).