Columbia subject headings:
Agriculture--Europe--History--Congresses.
Produce trade--Europe--Congresses.
Harvard subject headings:
Agriculture--Economic aspects--Europe--History--Congresses.
Peasants--Europe--History--Congresses.
Produce trade--Europe--History--Congresses.
Princeton subject headings:
Agriculture--Economic aspects--Europe--History--Congresses.
Peasants--Europe--History--Congresses.
Produce trade--Europe--History--Congresses.