Abubakar, Abdulhalim Musa, et al. “Microbial Growth Rate Kinetics in Biogas Production by Anaerobic Digestion of Chicken Manure”. IRASD Journal of Energy & Environment, vol. 3, no. 2, Dec. 2022, pp. 72-89, doi:10.52131/jee.2022.0302.0027.