Citation Hunt

The Wikipedia snippet below is not backed by a reliable source. Can you find one?

Click I got this! to go to Wikipedia and fix the snippet, or Next! to see another one. Good luck!

In page Turkic peoples:

"

Sometimes ethnographers group Turkic people into six branches: the Oghuz Turks, Kipchak, Karluk, Siberian, Chuvash, and Sakha/Yakut branches. The Oghuz have been termed Western Turks, while the remaining five, in such a classificatory scheme, are called Eastern Turks.[citation needed]