“Natural sorbents of the Black Soil Economical Region Report 2. Zeolites in the Upper Cretaceous rocks from the Belgorod and Kursk areas” (2019) Sorbtsionnye i Khromatograficheskie Protsessy, 10(3). Available at: https://journals.vsu.ru/sorpchrom/article/view/2064 (Accessed: 3 April 2026).