Columbia subject headings:
Ems River Valley (Germany and Netherlands)
Internationale Bauausstellung Emscher Park GmbH.
Regional planning--Ems River Valley (Germany and Netherlands)
Harvard subject headings:
Ems River Valley (Germany and Netherlands)--Buildings, structures, etc.
Industries--Environmental aspects--Ems River Valley (Germany and Netherlands)
Internationale Bauausstellung Emscher Park.
Regional planning--Germany--Ems River Valley (Germany and Netherlands)
Princeton subject headings: