Columbia subject headings:
Harvard subject headings:
Historical linguistics--Congresses.
Language maintenance--Congresses.
Language obsolescence--Congresses.
Language policy--Congresses.
Languages in contact--Congresses.
Linguistic minorities--Congresses.
Middle East--Languages--Social aspects.
Sociolinguistics--Congresses.
Princeton subject headings:
Comparative linguistics.
Europe, Eastern languages--Social aspects.
Language spread.
Linguistic minorities.
Middle East--Languages--Social aspects.
Oriental languages--Social aspects.
Sociolinguistics.