Elgin, Ceyhun, and Oğuz Öztunalı. “Environmental Kuznets Curve for the Informal Sector of Turkey (1950-2009)”. Panoeconomicus 61, no. 4 (April 2, 2014): 471–485. Accessed May 6, 2024. http://panoeconomicus.org/index.php/jorunal/article/view/484.