"Area Handbook for the Republic of Turkey", Volume 550, Issue 80, Thomas Duval Roberts, American University (Washington, D.C.). Foreign Area Studies. U.S. Government Printing Office, 1970. Page 74.
Vakalopoulos, Apostolos Euangelou. " Origins of the Greek Nation: The Byzantine Period, 1204-1461". Rutgers University Press, 1970. web link, p. 163, p. 330
Yusuf Durul: Flat-woven rugs made by "Yürüks". Ak Yayınları, 1977, page 60 cited: "The Turcomans, on the other hand, are of medium height, with fair hair and a fair complexion, and blue or greyish-blue eyes. They generally live in houses in the valleys and plains."
Insight Guides Turkey - Apa Publications (UK) Limited, 2015 cited: "Nomads (Yörüks) - Thought to be descendants of the Oguz Turkic tribe, many have preserved the fair complexion and green eyes of their ancestors;"