1. The National Priorities of Russian Fuel and Energy Complex.
https://neftrossii.ru/content/nacionalnye-prioritety-rossiyskogo-tek
2. Gas Production in Russia in 2018.
https://www.interfax.ru/russia/644896
3. International Monetary Fund: Report for Selected Countries and Subjects.
https://ur-l.ru/X35
4. Encyclopedia of Humanities: Research. centre for humanitarian technologies, 2006–2019.
https://gtmarket.ru/ratings/rating-countries-gdp/rating-countries-gdp-info
5. International Monetary Fund: Exports, FOB to Partner Countries.
http://data.imf.org/regular.aspx?key=61013712