Original: "The name al - Ir q, for all its Arabic appearance, is derived from Middle Persian er q 'lowlands'" W. Eilers (/O1983/O), "Iran and Mesopotamia" in E. Yarshater, The Cambridge History of Iran, vol.
Simplified: "Iran and Mesopotamia" in E. Yarshater, The Cambridge History of Iran, vol 3, Cambridge: Cambridge University Press.