Mažeikienė, Aušra, Marina Valentukevičienė, and Juozas Jankauskas. “Laboratory Study of Ammonium Ion Removal by Using Zeolite (clinoptilolite) to Treat Drinking Water”. Journal of Environmental Engineering and Landscape Management 18, no. 1 (March 31, 2010): 54-61. Accessed June 19, 2021. https://journals.vgtu.lt/index.php/JEELM/article/view/6068.