Anh, N., V. Thanh, B. Thuy, N. Hue, and T. Nhue. “MASS BALANCE AND ENERGY ANALYSIS OF A WASTEWATER SLUDGE ANAEROBIC DIGESTION SYSTEM FOR ENERGY RECOVERY”. Journal of Science and Technology in Civil Engineering (JSTCE) - HUCE, Vol. 10, no. 5, Oct. 2016, pp. 122-6, https://stce.huce.edu.vn/index.php/en/article/view/304.