Columbia subject headings:
Bulgars (Turkic people)--History.
Golden Horde--Relations--Kazanskoe khanstvo.
Kazanskoe khanstvo--Relations--Golden Horde.
Harvard subject headings:
Bulgars (Turkic people)--Russia (Federation)--Volga River Region--History.
Golden Horde--History
Kazanskoe khanstvo--History.
Mongols--History
Princeton subject headings:
Bulgars (Turkic people)--History.
Golden Horde--Relations--Kazanskoe khanstvo.
Kazanskoe khanstvo--Relations--Golden Horde.