721–747*Virasp Mehta, "Causes of the Downfall of the Sassanian Empire" (Palo Alto 2007)*Edward Gibbon, "The History of the Decline and Fall of the Roman Empire", chapter 46
721—747* Virasp Mehta, "Causes of the Downfall of the Sassanian Empire" (Palo Alto 2007)* Edward Gibbon, "The History of the Decline and Fall of the Roman Empire", chapter 46