Columbia subject headings:
Harvard subject headings:
Arid regions--Brazil, Northeast.
São Francisco River (Minas Gerais-Alagoas and Sergipe, Brazil)
Water-supply--Brazil, Northeast.
Water-supply--Brazil--São Francisco River Valley (Minas Gerais-Alagoas and Sergipe)
Princeton subject headings:
São Francisco River (Minas Gerais-Alagoas and Sergipe, Brazil)
Water-supply--Brazil--São Francisco River.