Columbia subject headings:
Catskill aqueduct.
Water-supply--New York (State)--New York.
Harvard subject headings:
Catskill Aqueduct (N.Y.)
Catskill aqueduct.
Water-supply--New York (State)--New York
Princeton subject headings:
Catskill Aqueduct (N.Y.)
Water-supply--New York (State)--New York.