Ozkan, Turgut, Gozde Yanginlar, and Salih Kalayci. 2018. “Testing the Transportation-Induced Environmental Kuznets Curve Hypothesis: Evidence from Eight Developed and Developing Countries”. International Journal of Energy Economics and Policy 9 (1):174-83. https://www.econjournals.com/index.php/ijeep/article/view/7330.