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 1122:

"
  • September 23 – The Concordat of Worms: Emperor Henry V recognizes freedom of election of the clergy and promises to restore all Church property. This brings an end to the power struggle between the papacy and the Holy Roman Empire, known as the Investiture Controversy. In the aftermath, Cappenberg Abbey is founded by Count Gottfried II for the new order of Premonstratensians.[citation needed]