Columbia subject headings:
Witnesses--Protection--Europe.
Harvard subject headings:
Witnesses--Protection--Europe.
Witnesses--Protection--European Union countries.
Witnesses--Services for--Europe.
Witnesses--Services for--European Union countries.
Princeton subject headings:
Witnesses--Protection--Europe.
Witnesses--Protection--European Union countries.
Witnesses--Services for--Europe.
Witnesses--Services for--European Union countries.