Y. Fransiscus and T. L. Simangunsong, “Anaerobic Digestion of Industrial Tempeh Wastewater with Sludge from Cow Manure Biogas Digester as Inoculum: Effect of F/M Ratio on the Methane Production”, Int. J. Adv. Sci. Eng. Inf. Technol., vol. 11, no. 3, pp. 1007–1013, Jun. 2021.