N. Tuan Minh, T. Van Tuyen, N. Thi Phuong Thao, P. Huu Tung, and T. Minh Viet, “Research on the recycling of waste activated sludge as an adsorbent material for ammonium removal in wastewater”, Vietnam J. Sci. Technol., vol. 60, no. 3, pp. 541–553, Jul. 2022.