Columbia subject headings:
Maps.
Russian language--Dialects--Russia, Northwestern--Etymology.
Russian language--Dialects--Russia, Northwestern--Maps.
Russian language--Foreign words and phrases--Baltic--Maps.
Russian language--Foreign words and phrases--Finno-Ugric--Maps.
Russian language--Foreign words and phrases--Turkic--Maps.
Substratum (Linguistics)
Harvard subject headings:
Russian language--Dialects--Russia, Northwestern--Etymology.
Russian language--Dialects--Russia, Northwestern--Maps.
Russian language--Foreign words and phrases--Baltic--Maps.
Russian language--Foreign words and phrases--Finno-Ugric--Maps.
Russian language--Foreign words and phrases--Turkic--Maps.
Substratum (Linguistics)
Princeton subject headings:
Russian language--Dialects--Maps.
Russian language--Etymology.
Russian language--Lexicology--Atlases.