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 Matilda of Sulzbach:

"

She was a daughter of Berengar II, Count of Sulzbach (c. 1080 – 3 December 1125)[citation needed] and his second wife Adelheid of Wolfratshausen. The identity of her mother is mentioned in the "Kastler Reimchronik", Vers 525.