https://www.gazeta.ru/comments/column/mironova/12099637.shtml
https://day.kyiv.ua/ru/article/podrobnosti/svyatoe-delo-i-kremlevskaya-agentura
The once-terrifying Russian military intelligence agency has been so sloppy and prone to fumbling that you have to ask: Why does a strongman brought up in the K.G.B. put up with it?
https://www.nytimes.com/2018/12/17/opinion/putins-keystone-spies.html
https://www.inopressa.ru/article/14Dec2018/wp/butina.html
http://www.dsnews.ua/world/butina-slilas-ili-ee-slili-14122018220000
https://theins.ru/opinions/132132
Looking at the investigation from the other side.
http://www.kasparov.ru/material.php?id=5C1202B64994A
https://www.gazeta.ru/science/2018/12/12_a_12092281.shtml