Dudin, M. N., Еvgenia Еvgenevna Frolova, V. N. Sidorenko, E. A. Pogrebinskaya, and I. V. Nikishina. “Energy Policy of the European Union: Challenges and Possible Development Paths”. International Journal of Energy Economics and Policy, vol. 7, no. 3, July 2017, pp. 294-9, https://www.econjournals.com/index.php/ijeep/article/view/5114.