“Some Sorption Characteristics of Silica Gel With Covalently Immobilized Pyridine-Containing Formazans”. Sorbtsionnye I Khromatograficheskie Protsessy, vol. 15, no. 5, Feb. 2018, pp. 649-56, https://doi.org/10.17308/sorpchrom.2015.15/317.