Nguyen, Phuong, and Phuoc Nguyen. “Enhancing Efficiency of Biogas Collection from Industrial Organic Sludge”. Science and Technology Development Journal 16, no. 1 (March 31, 2013): 84-94. Accessed January 3, 2025. http://stdj.scienceandtechnology.com.vn/index.php/stdj/article/view/1390.