Columbia subject headings:
Harvard subject headings:
German language--Foreign countries--Congresses.
German language--Social aspects--Europe--Congresses.
Languages in contact--Europe--Congresses.
Princeton subject headings:
Europe--Languages--Congresses.
German language--Europe--Congresses.
German language--Social aspects--Europe--Congresses.
Languages in contact--Congresses.
Linguistic change--Europe--Congresses.