Columbia subject headings:
Harvard subject headings:
Africa--Defenses--Congresses.
Mercenary troops--Africa--Congresses.
Mercenary troops--Africa.
National security--Africa--Congresses.
Police, Private--Africa.
Private security services--Africa--Congresses.
Private security services--Africa.
Princeton subject headings:
Africa--Defenses--Congresses.
Mercenary troops--Africa--Congresses.
National security--Africa--Congresses.
Private security services--Africa--Congresses.