Natalina, Hardoyo, Dede Ibnu, Veronica Situmorang, Cut Mutiawati, and Softanur, “The Used of Variuos Biomass Waste as Raw Material Biogass Production using Cow Dung as Source of Microbe by Continuously-Anaerobic Fermentation on the 15 Liter Reactor”, etj, vol. 9, no. 9, pp. 5060–5064, Sep. 2024.