Elysabeth1, Tiur, and Gina Ramayanti2. “Modification of Lampung and Bayah Natural Zeolite to Enhance the Efficiency of Removal of Ammonia from Wastewater”. Asian Journal of Chemistry, vol. 31, no. 4, Feb. 2019, pp. 873-8, doi:10.14233/ajchem.2019.21810.