Columbia subject headings:
Harvard subject headings:
Germany (East)--Economic conditions--Congresses.
Germany (East)--History--Congresses.
Germany--Economic conditions--20th century--Congresses.
Germany--History--20th century--Congresses.
Princeton subject headings:
Germany (East)--Economic conditions--Congresses.
Germany (East)--History--Congresses.
Germany--Economic conditions--20th century--Congresses.
Germany--History--20th century--Congresses.