Columbia subject headings:
Arid regions agriculture--Sahel.
Desertification--Sahel.
Sahel--Economic conditions.
Harvard subject headings:
Arid regions agriculture--Sahel.
Desertification--Sahel.
Sahel--Economic conditions.
Princeton subject headings:
Desertification--Sahel.
Environmental policy--Sahel.
Human ecology--Sahel.