Columbia subject headings:
Europe, Central--Relations--Europe--Congresses.
Europe, Eastern--Relations--Europe--Congresses.
Europe--Relations--Europe, Central--Congresses.
Europe--Relations--Europe, Eastern--Congresses.
European Union--Europe, Eastern--Congresses.
Harvard subject headings:
Europe, Central--Relations--Europe--Congresses.
Europe, Eastern--Relations--Europe--Congresses.
Europe--Relations--Europe, Central--Congresses.
Europe--Relations--Europe, Eastern--Congresses.
European Union--Europe, Eastern--Congresses.
Princeton subject headings: