K. H. Menges, in Encyclopaedia Iranica （页面存档备份，存于互联网档案馆） Excerpt: "In a series of relatively minor movements, Turkic groups began to occupy territories in western Central Asia and eastern Europe which had previously been held by Iranians (i.e. , Turan). The Volga Bulgars, following the Avars, proceeded to the Volga and Ukraine in the 6th-7th centuries."
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K. H. Menges, in Encyclopaedia Iranica （页面存档备份，存于互联网档案馆） Excerpt: "In a series of relatively minor movements, Turkic groups began to occupy territories in western Central Asia and eastern Europe which had previously been held by Iranians (i.e. , Turan). The Volga Bulgars, following the Avars, proceeded to the Volga and Ukraine in the 6th-7th centuries."
