Columbia subject headings:
Harvard subject headings:
Architecture, Medieval--Germany--To 1500.
Castles--Germany--Water-supply--History--To 1500.
Fortification--Germany--Water-supply--History--To 1500.
Water-supply--Germany--History--To 1500.
Wells--Germany--Design and construction--History--To 1500.
Princeton subject headings:
Architecture, Medieval--Germany--To 1500.
Castles--Germany--Water-supply--History--To 1500.
Fortification--Germany--Water-supply--History--To 1500.
Water-supply--Germany--History--To 1500.
Wells--Germany--Design and construction--History--To 1500.