Columbia subject headings:
Harvard subject headings:
Bili︠a︡r (Extinct city)
Bulgars (Turkic people)--Russia (Federation)--Tatarstan.
Excavations (Archaeology)--Russia (Federation)--Tatarstan.
Russia (Federation)--Antiquities.
Tatarstan (Russia)--Antiquities.
Volga River Region (Russia)--Antiquities.
Princeton subject headings:
Russia (Federation)--Antiquities.
Volzhsko-Kamskai︠a︡ Bulgarii︠a︡ (R.S.F.S.R.)--Antiquities.