https://www.bbc.com/russian/news-46962252
https://www.gazeta.ru/business/2019/01/21/12137287.shtml
https://www.gazeta.ru/politics/2019/01/22_a_12138889.shtml
http://expert.ru/2019/01/22/kurilyi-torg-umesten/
https://www.kommersant.ru/doc/3860529
https://www.radiosvoboda.org/a/news-hazprom-ukrajina-haz-kontrakt/29722712.html
https://www.inopressa.ru/article/21Jan2019/lefigaro/potok.html