Sukono, Sukono, et al. “The Effect of Gross Domestic Product and Population Growth on CO2 Emissions in Indonesia: An Application of the Ant Colony Optimisation Algorithm and Cobb-Douglas Model”. International Journal of Energy Economics and Policy, vol. 9, no. 4, June 2019, pp. 313-9, https://econjournals.net.tr/index.php/ijeep/article/view/8011.