Columbia subject headings:
European Union countries--Relations--Poland--Congresses.
European Union--Poland--Congresses.
Poland--Relations--European Union countries--Congresses.
Harvard subject headings:
European Union countries--Relations--Poland--Congresses.
European Union--Poland--Congresses.
Poland--Relations--European Union countries--Congresses.
Princeton subject headings:
European Union countries--Relations--Poland--Congresses.
European Union--Poland--Congresses.
Poland--Relations--European Union countries--Congresses.