Tsegaye, D., M. Dawit, and K. Gajananda. “Anaerobic Digestion of Tannery Solid Waste for Biogas Production: The Case of Modjo Tannery, Modjo; Ethiopia”. Journal of Technology Innovations in Renewable Energy, vol. 5, no. 2, July 2016, pp. 68-75, doi:10.6000/1929-6002.2016.05.02.4.