http://www.ng.ru/columnist/2019-12-25/100_column2512.html
https://www.kommersant.ru/doc/4206753
SOFIA, Bulgaria -- The Russian assassin used an alias, Sergei Fedotov, and slipped into Bulgaria unnoticed, checking into a hotel in Sofia near the office of a local arms manufacturer who had been selling ammunition to Ukraine.He led a team of three men.Within days, one man sneaked into a locked parking
https://news.yahoo.com/poisoning-bulgaria-exposed-russian-assassins-133100185.html
https://www.inopressa.ru/article/23Dec2019/nytimes/gebrev.html
http://www.ng.ru/vision/2019-12-23/6_7759_vision.html
https://www.mk.ru/politics/2019/12/23/v-chem-okazalsya-ne-prav-putin-v-khode-presskonferencii.html
http://www.ng.ru/ideas/2019-12-23/7_7759_constitution.html
http://www.ng.ru/politics/2019-12-23/100_echo23122019.html