Mukumba, Patrick, Golden Makaka, and Sampson Mamphweli. “Biogas Technology in South Africa, Problems, Challenges and Solutions”. International Journal of Sustainable Energy and Environmental Research 5, no. 4 (November 8, 2016): 58–69. Accessed February 4, 2026. https://www.archive.conscientiabeam.com/index.php/13/article/view/2115.