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