Columbia subject headings:
Arid regions agriculture--Congresses.
Arid regions--Congresses.
Desertification--Congresses.
Geomorphology--Arid regions--Congresses.
Harvard subject headings:
Arid regions agriculture--Congresses.
Arid regions--Congresses
Desertification--Congresses
Geomorphology--Arid regions--Congresses.
Princeton subject headings:
Arid regions agriculture--Congresses.
Arid regions--Congresses.
Desertification--Congresses.
Geomorphology--Arid regions--Congresses.