Дмитриев, Д. А., А. Д. Савко, С. А. Куролап, В. Н. Калаев, and Д. А. Иванов. “Mineral-Raw Material Base of Non-Metallic Mineral Resources of Central Black Earth Region and Its Rational Use. Article 2. The Model of Rational Using of Mineral-Raw Material Base of Non-Metals”. Proceedings of Voronezh State University. Series: Geology, no. 4, Oct. 2018, pp. 39-56, doi:10.17308/geology.2018.4/1646.