Columbia subject headings:
Harvard subject headings:
Aggressiveness--Europe--Congresses.
Europe--Politics and government--Congresses.
European Union--Economic integration--Congresses.
Violence--Europe--Congresses.
Princeton subject headings:
Aggressiveness--Europe--Congresses.
Europe--Politics and government--Congresses.
European Union--Economic integration--Congresses.
Violence--Europe--Congresses.