Mažeikienė, Aušra, Marina Valentukevičienė, and Juozas Jankauskas. 2010. “Laboratory Study of Ammonium Ion Removal by Using Zeolite (clinoptilolite) to Treat Drinking Water”. Journal of Environmental Engineering and Landscape Management 18 (1):54-61. https://doi.org/10.3846/jeelm.2010.07.