Columbia subject headings:
Europe--Economic integration--Congresses.
European Union--Germany--Congresses.
European Union--Hungary--Congresses.
Harvard subject headings:
European Union--Foreign relations--Germany--Congresses.
European Union--Foreign relations--Hungary--Congresses.
Germany--Foreign relations--European Union countries--Congresses.
Hungary--Foreign relations--European Union countries--Congresses.
Princeton subject headings: