GRAMA, Yulia. The Analysis of Russian Oil and Gas Reserves. International Journal of Energy Economics and Policy, [S. l.], v. 2, n. 2, p. 82–91, 2012. Disponível em: https://mail.econjournals.org.tr/index.php/ijeep/article/view/185. Acesso em: 26 jan. 2025.