Effiong, M. O., C. U. Okoye, and N. J. Nweze. “Sectoral Contributions to Carbon Dioxide Equivalent Emissions in the Nigerian Economy”. International Journal of Energy Economics and Policy, vol. 10, no. 1, Nov. 2019, pp. 456-63, https://econjournals.com/index.php/ijeep/article/view/8905.