Columbia subject headings:
Harvard subject headings:
Europe, Central--Emigration and immigration--Congresses.
Europe, Central--Ethnic relations--Congresses.
Europe, Eastern--Emigration and immigration--Congresses.
Europe, Eastern--Ethnic relations--Congresses.
Minorities--Europe, Central--Congresses.
Minorities--Europe, Eastern--Congresses.
Princeton subject headings:
Europe, Central--Emigration and immigration--Congresses.
Europe, Central--Ethnic relations--Congresses.
Europe, Eastern--Emigration and immigration--Congresses.
Europe, Eastern--Ethnic relations--Congresses.
Minorities--Europe, Central--Congresses.
Minorities--Europe, Eastern--Congresses.