Columbia subject headings:
Harvard subject headings:
Nazi concentration camp inmates--Germany--Correspondence
Sachsenhausen (Concentration camp)--History.
World War, 1939-1945--Concentration camps--Germany--History.
Princeton subject headings:
Sachsenhausen (Concentration camp)
Sachsenhausen (Concentration camp)--History--Sources.
World War, 1939-1945--Prisoners and prisons, German--Sources.
World War, 1939-1945--Prisoners and prisons, German.