“Petrographic characteristics of the granite gneisses of the Usmanskiy Pinewood forest: towards the origin of the ‘Kudeyarov stones’ in the Voronezh State Nature Biosphere Reserve” (2020) Proceedings of Voronezh State University. Series: Geology, (4), pp. 87–93. doi:10.17308/geology.2020.4/3131.