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