Columbia subject headings:
European Union countries--Emigration and immigration--Government policy.
Illegal immigration--European Union countries.
Noncitizens--European Union countries.
Harvard subject headings:
European Union countries--Emigration and immigration--Government policy
Illegal immigration--European Union countries.
Noncitizens--European Union countries
Princeton subject headings:
European Union countries--Emigration and immigration--Government policy.
Illegal aliens--European Union countries.