https://tyzhden.ua/%D0%A1%D0%B2%D1%96%D1%82/253450
https://www.nytimes.com/2021/10/25/us/politics/russia-cybersurveillance-biden.html
http://www.kasparov.ru/material.php?id=617293B719EFC
http://region.expert/republic/
https://lansinginstitute.org/2021/10/12/russian-intelligence-focus-in-bulgaria/
https://novayagazeta.ru/articles/2021/10/07/svoikh-ne-raskryvaem