Columbia subject headings:
Bulgaria--History--681-1018--Chronology.
Bulgaria--Kings and rulers.
Bulgars (Turkic people)--Kings and rulers.
Calendar, Bulgaro-Turkic.
Imennik na bŭlgarskite khanove.
Harvard subject headings:
Bulgaria--History--681-1018--Chronology.
Bulgaria--Kings and rulers.
Bulgars (Turkic people)--Kings and rulers.
Calendar, Bulgaro-Turkic.
Imennik na bŭlgarskite khanove.
Princeton subject headings:
Bulgaria--History--681-1018--Sources.
Bulgaria--Kings and rulers.
Bulgars (Turkic people)--Kings and rulers.