Nguyen Trung Hiep, Le Thi Hong Tuyet, Dinh Thi Nga, and Phan Dinh Tuan. “A Research on the Performance of down-Flow Hanging Sponge (DHS) Reactor Treating Domestic Wastewater”. Vietnam Journal of Science and Technology 56, no. 4 (August 6, 2018): 482–492. Accessed March 12, 2026. https://vjs.ac.vn/jst/article/view/10878.