Yılmaz Öztuna, Devletler ve hânedanlar: Türkiye : 1074 - 1990, Vol.2, Türkiye Kültür Bakanlığı, 2005, p.51, Online Edition
John Freely, The companion guide to Turkey, HarperCollins, 1993, p.391, Online Edition "This was erected in 1339 by Eretna, an Uyghur Turk who created an independent principality in central Anatolia after the collapse of the Ilkhanid Mongol Empire in 1335."
Jonathan M. Bloom, Sheila Blair, Oxford University Press, 2009, p.60, Online Edition "In the early 14th century, the city passed to the Uighur chief Eretna."
Speros Vryonis, The decline of medieval Hellenism in Asia Minor: and the process of Islamization from the eleventh through the fifteenth century, (Berkeley: University of California, 1971), p. 139, Online Edition "When the governor Timurlash fled to Egypt in 1327, he was replaced by Ghiyath al-Din Eretna (of Uighur origin) who succeeded in receiving official appointment from the Ilkhan Abu Sa'id."
Ibn Batuta, Sir Hamilton Alexander Rosskeen Gibb, Travels of Ibn Battuta, A.D. 1325-1354, Published for the Hakluyt Society at the University Press, 1962, p. 433. "Ertena, a Mongol officer under the Chobanid Timurtash"
