Columbia subject headings:
Languages in contact--Europe--Congresses.
Linguistic minorities--Europe--Congresses.
Multilingualism--Europe--Congresses.
Harvard subject headings:
Languages in contact--Europe--Congresses.
Linguistic minorities--Europe--Congresses.
Multilingualism--Europe--Congresses.
Princeton subject headings:
Europe--Languages--Congresses.
German language--Europe--Congresses.
German language--Foreign countries--Congresses.
Linguistic minorities--Europe--Congresses.