Dontsova, T., S. Nagirnyak, G. Krymets, O. Melnichuk, I. Bashmakov, and D. Skladannyy. “An Alternative Method of Silica Gel Synthesis of Ukrainian Raw Materials”. Catalysis and Petrochemistry, no. 27, Nov. 2018, pp. 41-46, http://kataliz.org.ua/index.php/journal/article/view/54.