V. S. Levitskiy, A. S. Lenshin, A. I. Maximov, E. V. Maraeva, and V. A. Moshnikov, “Formation peculiarities of metal oxide porous structures in SiO2 – SnO2 and SiO2 – CoO sol-gel systems”, sorpchrom, vol. 12, no. 5, Nov. 2019.