Columbia subject headings:
Harvard subject headings:
Europe--Emigration and immigration--History--Congresses.
Europe--Emigration and immigration--Social aspects--Congresses.
Immigrants--Cultural assimilation--Europe--Congresses.
Intergroup relations--Europe--History--Congresses.
Social integration--Europe--History--Congresses.
Princeton subject headings:
Europe--Emigration and immigration--History--Congresses.
Europe--Emigration and immigration--Social aspects--Congresses.
Immigrants--Cultural assimilation--Europe--Congresses.
Intergroup relations--Europe--History--Congresses.
Social integration--Europe--History--Congresses.