Columbia subject headings:
Harvard subject headings:
Hydronymy
Names, Geographical--Russia (Federation)--Oka River watershed (Kurskai︠a︡ oblastʹ-Nizhegorodskai︠a︡ oblastʹ)
Oka River watershed (Kurskai︠a︡ oblastʹ-Nizhegorodskai︠a︡ oblastʹ, Russia)--Gazetteers.
Princeton subject headings:
Hydronymy.
Names, Geographical--Russia (Federation)--Oka River watershed.
Oka River watershed (Russia)--Gazetteers.