Columbia subject headings:
Harvard subject headings:
Europe--Economic conditions--Congresses.
Europe--Rural conditions--Congresses.
Labor market--Europe--Congresses.
Labor--Europe--Congresses.
Rural-urban migration--Europe--Congresses.
Princeton subject headings:
Europe--Economic conditions--Congresses.
Europe--Rural conditions--Congresses.
Labor market--Europe--History--Congresses.
Labor--Europe--History--Congresses.
Rural-urban migration--Europe--Congresses.