Columbia subject headings:
Agriculturally marginal lands--History--Congresses.
Land settlement patterns, Prehistoric--Congresses.
Harvard subject headings:
Agriculturally marginal lands--History--Congresses.
Environmental archaeology--Congresses.
Land settlement patterns, Prehistoric--Congresses.
Princeton subject headings:
Agriculturally marginal lands--History--Congresses.
Environmental archaeology--Congresses.
Land settlement patterns, Prehistoric--Congresses.