Kats, E. M., V. A. Nikashina, and J. V. Bichkova. “The Kinetic Sorption of Heavy Metals from Surface Water on Natural and Modified Polyethilenimine Clinoptilolite of Holinsky Deposit”. Sorbtsionnye I Khromatograficheskie Protsessy, Vol. 16, no. 1, Nov. 2019, pp. 36-43, https://journals.vsu.ru/sorpchrom/article/view/1322.