Columbia subject headings:
Civil rights--Belgium--Congresses.
Civil rights--Europe--Congresses.
National security--Belgium--Congresses.
National security--Europe--Congresses.
Terrorism--Belgium--Prevention--Congresses.
Terrorism--Europe--Prevention--Congresses.
Harvard subject headings:
Civil rights--Belgium--Congresses.
Civil rights--Europe--Congresses
National security--Belgium--Congresses.
National security--Europe--Congresses
Terrorism--Belgium--Prevention--Congresses.
Terrorism--Europe--Prevention--Congresses.
Princeton subject headings: