Columbia subject headings:
Africa, North--Antiquities--Congresses.
Water-supply--Africa, North--History--Congresses.
Harvard subject headings:
Africa, North--Antiquities--Congresses.
Water-supply--Africa, North--History--Congresses.
Princeton subject headings:
Africa, North--Antiquities--Congresses.
Water-supply--Africa, North--History--Congresses.