Columbia subject headings:
Russian language--To 1300--Dialects.
Russian language--To 1300--Phonology.
Harvard subject headings:
Russian language--Old Russian--Dialects.
Russian language--Old Russian--Phonology.
Russian language--To 1300--Dialects.
Russian language--To 1300--Phonology.
Princeton subject headings:
Russian language--Old Russian--Dialects.
Russian language--Old Russian--Phonology.