Columbia subject headings:
Harvard subject headings:
Linguistic minorities--Europe--Congresses.
Minorities--Europe--Congresses
Nationalism--Europe--History--Congresses.
Princeton subject headings:
Danes--Germany--Ethnic identity.
Frisians--Germany--Ethnic identity.
Minorities--Europe.
Minorities--Germany.
Romanies--Germany--Ethnic identity.
Sorbs--Germany--Ethnic identity.