Analysis of information sources in references of the Wikipedia article "Kidarites" in English language version.
Armenian geographer states that the principal tribes of Bulgars were called Kuphi-Bulgars, Duchi-Bulgars, Oghkhundur-Bulgars, and Kidar-Bulgars, by the last-named of which he meant the Kidarites, a branch of the Huns.
Apart from Gandhara, however, a Kidarite kingdom may have survived in Sogdiana, possibly in the area of Ustrushana.
However, we should not assume that the Kidarite presence in eastern Sogdiana disappeared quickly after their demise in Tokharistan. Indeed, centuries later, in the early ninth century, the local king of Ustrushana and the Abbasid general Al-Afshin bore the personal name of Khydhar...
The Yueh-chih origin of Kidara is clearly established...