Columbia subject headings:
Water conservation--Yemen (Republic)--Taʻizz.
Water resources development--Environmental aspects--Yemen (Republic)--Taʻizz.
Water-supply--Yemen (Republic)--Taʻizz.
Harvard subject headings:
Water conservation--Yemen (Republic)--Taʻizz.
Water conservation--Yemen--Taʻizz.
Water resources development--Environmental aspects--Yemen (Republic)--Taʻizz.
Water resources development--Environmental aspects--Yemen--Taʻizz.
Water-supply--Yemen (Republic)--Taʻizz.
Water-supply--Yemen--Taʻizz.
Princeton subject headings:
Water conservation--Yemen--Taʻizz.
Water resources development--Environmental aspects--Yemen--Taʻizz.
Water-supply--Yemen--Taʻizz.