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. geology [Internet]. 2020 Dec. 1 [cited 2026 Mar. 30];(4):87-93. Available from: https://journals.vsu.ru/geology/article/view/3131