Columbia subject headings:
Harvard subject headings:
European Union countries--Defense--Congresses.
European Union--Congresses.
National security--Europe--Congresses
North Atlantic Treaty Organization--Armed Forces--Organization.
North Atlantic Treaty Organization--Congresses.
North Atlantic Treaty Organization--Defenses--Congresses.
North Atlantic Treaty Organization--Membership--Congresses.
North Atlantic Treaty Organization--Membership.
North Atlantic Treaty Organization--Military policy--Congresses.
North Atlantic Treaty Organization--Planning.
North Atlantic Treaty Organization--Reorganization.
Princeton subject headings:
North Atlantic Treaty Organization--Armed Forces--Organization.
North Atlantic Treaty Organization--Membership.
North Atlantic Treaty Organization--Planning.
North Atlantic Treaty Organization--Reorganization.