Columbia subject headings:
Harvard subject headings:
Water resources development--Czechoslovakia--History--20th century.
Water resources development--Romania--History--20th century.
Water use--Czechoslovakia--History--20th century.
Water use--Romania--History--20th century.
Water-supply--Czechoslovakia--Management--History--20th century.
Water-supply--Romania--Management--History--20th century.
Princeton subject headings:
Water-supply--Czechoslovakia--History.
Water-supply--Romania--History.