Columbia subject headings:
Emigration and immigration--Social aspects.
Emigration and immigration.
European Union countries--Emigration and immigration--Government policy.
European Union.
Harvard subject headings:
Emigration and immigration
Emigration and immigration--Social aspects
European Union
European Union countries--Emigration and immigration--Government policy.
Princeton subject headings:
Emigration and immigration--Social aspects.
Emigration and immigration.
European Union countries--Emigration and immigration--Government policy.
European Union.