Bashir, A., K. M. H. Thamrin, M. Farhan, M. Mukhlis, and D. P. Atiyatna. “The Causality Between Human Capital, Energy Consumption, CO2 Emissions, and Economic Growth: Empirical Evidence from Indonesia”. International Journal of Energy Economics and Policy, vol. 9, no. 2, Feb. 2019, pp. 98-104, https://www.econjournals.com/index.php/ijeep/article/view/7377.