Eboibi, B. “ANAEROBIC DIGESTION OF COW MANURE: INFLUENCE OF HYDRAULIC RETENTION TIME ON BIOGAS YIELD AND PROPERTIES OF DIGESTATE”. LAUTECH Journal of Engineering and Technology, Vol. 14, no. 1, Jan. 2020, pp. 87-97, https://laujet.com/index.php/laujet/article/view/366.