1833, Researches of the Rev. E. Smith and Rev. H.G.O. Dwight in Armenia:
The sons of Seljook, when sultáns of a vast empire, retained the wandering habits of their ancestor, who pitched his shepherd's tent upon the banks of the Jihon.
1838, Historical causes and effects:
After subjecting the Arabians, they founded a vast empire, under the name of the Seljooks, or Seljoukians, so called from the name of Seljook, the first distinguished chief of this people.
1853, The Encyclopædia Britannica:
His successors Alp Arslan and Malek Shah extended name of their renowned chief Seljook, who, being banished the empire transmitted to them by Togrul Beg.