Columbia subject headings:
Europe--Emigration and immigration.
Foreign workers--Europe.
Foreign workers--Germany.
Labor mobility--Europe.
Migrant labor--Europe.
Harvard subject headings:
Europe--Emigration and immigration.
Foreign workers--Europe
Foreign workers--Germany.
Labor mobility--Europe.
Migrant labor--Europe.
Princeton subject headings:
Europe--Emigration and immigration.
Foreign workers--Europe.
Foreign workers--Germany.
Labor mobility--Europe.
Migrant labor--Europe.