Columbia subject headings:
Germany--History--20th century.
Germany--Relations--Poland.
Poland--History--20th century.
Poland--Relations--Germany.
Polish people--Germany (East)--Social conditions.
Polish people--Germany (West)--Social conditions.
World War, 1914-1918.
World War, 1939-1945--Refugees.
Harvard subject headings:
Germans--Poland--Social conditions.
Germany--History--20th century.
Germany--Relations--Poland.
Poland--History--20th century
Poland--Relations--Germany
Polish people--Germany (East)--Social conditions.
Polish people--Germany (West)--Social conditions.
World War, 1914-1918
World War, 1939-1945--Refugees--Germany.
World War, 1939-1945--Refugees--Poland.
Princeton subject headings:
Germany--History--20th century.
Germany--Relations--Poland.
Poland--History--20th century.
Poland--Relations--Germany.
Polish people--Germany (East)--Social conditions.
Polish people--Germany (West)--Social conditions.
World War, 1914-1918.
World War, 1939-1945--Refugees.