Columbia subject headings:
Developing countries--Water-supply--Congresses.
Water resources development--Africa--Congresses.
Water resources development--Asia--Congresses.
Water resources development--Canada--Congresses.
Water resources development--Europe--Congresses.
Harvard subject headings:
Environmental health--Developing countries--Congresses.
Sanitary engineering--Developing countries--Congresses.
Water-supply--Developing countries--Congresses.
Princeton subject headings: