Columbia subject headings:
Harvard subject headings:
Europe, Central--Economic integration--History--20th century--Congresses.
Europe, Central--Relations--Congresses.
Europe, Eastern--Economic integration--History--20th century--Congresses.
Europe, Eastern--Relations--Congresses.
European cooperation--History--20th century--Congresses.
European federation--History--20th century--Congresses.
International cooperation--Congresses
Paneuropa-Union--History--20th century--Congresses.
Princeton subject headings:
Europe, Central--Economic integration--History--20th century--Congresses.
Europe, Central--Relations--Congresses.
Europe, Eastern--Economic integration--History--20th century--Congresses.
Europe, Eastern--Relations--Congresses.
European cooperation--History--20th century--Congresses.
European federation--History--20th century--Congresses.
International cooperation--Congresses.
Paneuropa-Union--History--20th century--Congresses.