Humnytskyy, Yaroslav     Statics and kinetics of ammonium nitrogen sorption on natural zeolite under periodic conditions [Текст] / Yaroslav Humnytskyy, Oksana Matsuska // Chemistry & Chemical Technology / Lviv Polytechnic Nat. Univ. ; ed.-in-chief M. Bratychak. — Lviv : Publ. House of Lviv Polytechnic Nat. Univ., 2011. — P. 7-11.