Columbia subject headings:
Harvard subject headings:
Drinking water--Germany--Karlsruhe--History--Exhibitions.
Drinking water--Standards--Germany--Karlsruhe--History--Exhibitions.
Water resources development--Germany--Karlsruhe--History--Exhibitions.
Water use--Germany--Karlsruhe--History--Exhibitions.
Water-supply--Germany--Karlsruhe--History--Exhibitions.
Princeton subject headings:
Drinking water--Germany--Karlsruhe--History--Exhibitions.
Drinking water--Standards--Germany--Karlsruhe--History--Exhibitions.
Water resources development--Germany--Karlsruhe--History--Exhibitions.
Water use--Germany--Karlsruhe--History--Exhibitions.
Water-supply--Germany--Karlsruhe--History--Exhibitions.