Sharapiyeva, M. D., K. Duissekul, N. Gulmira, and K. Zhanna. “Energy Efficiency of Transport and Logistics Infrastructure: The Example of the Republic of Kazakhstan”. International Journal of Energy Economics and Policy, vol. 9, no. 5, July 2019, pp. 331-8, https://econjournals.com/index.php/ijeep/article/view/8204.