Columbia subject headings:
Bilbao (Spain)--Languages.
Sociolinguistics--Spain--Bilbao.
Spanish language--Dialects--Spain--Bilbao.
Harvard subject headings:
Basque language--Social aspects--Spain--Bilbao.
Bilbao (Spain)--Languages.
Sociolinguistics--Spain--Bilbao.
Princeton subject headings:
Bilbao (Spain)--Languages.
Sociolinguistics--Spain--Bilbao.
Spanish language--Dialects--Spain--Bilbao.