Columbia subject headings:
Harvard subject headings:
Cities and towns--Germany--History
Sister cities--Case studies.
Trier (Germany)--Relations--Germany--Weimar (Thuringia)
Weimar (Thuringia, Germany)--Relations--Germany--Trier.
Princeton subject headings:
Germany (East)--Relations--Germany (West)
Germany (West)--Relations--Germany (East)
Sister cities.
Trier (Germany)--Politics and government.
Weimar (Thuringia, Germany)--Politics and government.