Columbia subject headings:
Harvard subject headings:
Czechoslovakia--History--20th century.
Germany (East)--Boundaries.
Germany (East)--History.
Germany (East)--Politics and government.
Poland--History--20th century
Princeton subject headings:
Czechoslovakia--Boundaries--Germany (East).
Germany (East)--Boundaries--Czechoslovakia.
Germany (East)--Boundaries--Poland.
Poland--Boundaries--Germany (East)