Columbia subject headings:
Harvard subject headings:
European Union countries--Emigration and immigration--Economic aspects.
Foreign workers--European Union countries
Labor market--European Union countries.
Labor mobility--European Union countries.
Migration, Internal--Economic aspects--European Union countries.
Princeton subject headings:
European Union countries--Emigration and immigration--Economic aspects.
Foreign workers--European Union countries.
Labor market--European Union countries.
Labor mobility--European Union countries.
Migration, Internal--Economic aspects--European Union countries.