Nguyen Dinh Tung, Nguyen Van Tien, and Nguyen Dinh Quy. “RESEARCHING, DESIGNING AND MANUFACTURING BIOFILTER”. UTEHY Journal of Applied Science and Technology, Vol. 35, Sept. 2022, pp. 90-95, http://jst.utehy.edu.vn/index.php/jst/article/view/562.