Columbia subject headings:
Agriculture--Economic aspects--Europe--History--Congresses.
Europe--Economic conditions--To 1492--Congresses.
Europe--History--476-1492--Congresses.
Farms--Europe--History--Congresses.
Harvard subject headings:
Agriculture--Economic aspects--Europe--History--Congresses.
Europe--Economic conditions--To 1492--Congresses.
Farms--Europe--History--Congresses.
Princeton subject headings:
Agriculture--Economic aspects--Europe--History--Congresses.
Europe--Economic conditions--To 1492--Congresses.
Europe--History--476-1492--Congresses.
Farms--Europe--History--Congresses.