Columbia subject headings:
France--Population--History--Congresses.
France--Rural conditions--Congresses.
Germany--Population--History--Congresses.
Germany--Rural conditions--Congresses.
Urbanization--France--History--Congresses.
Urbanization--Germany--History--Congresses.
Harvard subject headings:
France--Population--History--Congresses.
France--Rural conditions--Congresses.
Germany--Population--History--Congresses.
Germany--Rural conditions--Congresses.
Urbanization--France--History--Congresses.
Urbanization--Germany--History--Congresses.
Princeton subject headings:
France--Population--History--Congresses.
France--Rural conditions--Congresses.
Germany--Population--History--Congresses.
Germany--Rural conditions--Congresses.
Urbanization--France--History--Congresses.
Urbanization--Germany--History--Congresses.