http://www.ng.ru/week/2018-02-04/7_7165_economy.html
https://ru.krymr.com/a/29016345.html
Russia has the best oil and gas companies in the world, according to S&P Platts.
https://www.forbes.com/sites/kenrapoza/2018/02/02/russia-tops-u-s-in-global-energy-company-rankings/
http://www.rosbalt.ru/world/2018/02/02/1679421.html
https://www.kommersant.ru/doc/3539537
https://www.kommersant.ru/doc/3535314
http://www.ng.ru/cis/2018-01-31/100_obzor310118.html
https://www.gazeta.ru/business/2018/01/31/11631955.shtml