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 Keratsa of Bulgaria:

"

Sometime before 1392, but after Andronikos' death, Keratsa-Maria became a nun, taking the name Makaria. According to Alice-Mary Talbot, taking this status after becoming a widow was not uncommon at the time to ensure financial security. Additionally, becoming a nun gave wealthy women opportunity to recover control of their dowries to use them for pious purposes.[1] Perhaps this was how Keratsa was able to exercise charity to the extent she did while being an empress. When Keratsa became senior empress in 1399, she was still a nun.[citation needed][a]