Jimenez-Islas, D., M. E. Perez-Romero, I. V. Cruz, and M. B. Flores-Romero. “Development of Biofuels Research in South Africa”. International Journal of Energy Economics and Policy, vol. 11, no. 5, Aug. 2021, pp. 99-105, https://econjournals.com/index.php/ijeep/article/view/11454.