Columbia subject headings:
Harvard subject headings:
Europe--Economic conditions--20th century--Congresses.
Europe--Politics and government--20th century--Congresses.
Europe--Social conditions--20th century--Congresses.
European Union--Congresses.
Germany--Economic conditions--20th century--Congresses.
Germany--Politics and government--20th century--Congresses.
Germany--Social conditions--20th century--Congresses.
Princeton subject headings:
Europe--Economic conditions--20th century--Congresses.
Europe--Politics and government--20th century--Congresses.
Europe--Social conditions--20th century--Congresses.
European Union--Congresses.
Germany--Economic conditions--20th century--Congresses.
Germany--Politics and government--20th century--Congresses.
Germany--Social conditions--20th century--Congresses.