Apergis, Nicholas, and Dan Constantin Danuletiu. “Renewable Energy and Economic Growth: Evidence from the Sign of Panel Long-Run Causality”. International Journal of Energy Economics and Policy 4, no. 4 (August 25, 2014): 578–587. Accessed March 28, 2024. https://www.econjournals.com/index.php/ijeep/article/view/879.