Rezakhani 2017, p. 178, According to Rezakhani, coins of the years 3-5 (582-584) of the reign of Hormizd IV (579–590) were minted in Khulm and Samarkand, and coins of year 6 (585) were minted in Chach, and should "probably" be assigned to this period, attesting to the "northernmost extent of Sasanian power, extending beyond the Syr Darya/Jaxartes" p.176. Rezakhani, Khodadad (2017). ReOrienting the Sasanians: East Iran in Late Antiquity. Edinburgh University Press. pp. 1–256. ISBN9781474400305.