毘伽可汗
In the Bain Tsokto inscriptions of 720s erected by Tonyukuk, the name "Türük" "Turks" is mostly accompanied by the name "(E)Sir" (Old Turkic script: 𐰾𐰃𐰼). According to S.G.Klyashtorny and T.İ. Sultanov this shows the importance of Sir element in the Second Turkic Khaganate (681-744) This opinion is possibly supported by the fact that in the Khöshöö Tsaidam Monuments erected in 735 for Bilge Khagan, the name "Sir" follows the name "Türük" and precedes other tribal names.