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 Frisia:

This text has been unreferenced on Wikipedia for a very long time. If you can't find a source, be bold and remove it!

This text is part of the article's lead section, so referencing it may be optional. Please see WP:CITELEAD for more information.

"

Around 1040, Matilda of Frisia gave birth to a daughter via Caesarian section,[citation needed] but four years later in 1044 both she and her daughter died only weeks apart.[8] Matilda was buried in St Denis Abbey, but her tomb is not preserved.