Columbia subject headings:
Europe--Emigration and immigration.
Immigrants--Europe.
Mediterranean Region--Emigration and immigration.
Refugees--Europe.
Harvard subject headings:
European Union countries--Emigration and immigration.
Mediterranean Region--Emigration and immigration.
Public opinion--European Union countries--21st century.
Public opinion--Mediterranean Region--21st century.
Refugees--European Union countries--21st century--Public opinion.
Refugees--Mediterranean Region--21st century--Public opinion.
Princeton subject headings:
Europe--Emigration and immigration.
Immigrants--Europe.
Mediterranean Region--Emigration and immigration.
Refugees--Europe.