Fedotov, Sergey V., and Vladimir I. Fedotov. “Correspondence Not Delivered To the Addressee”. Proceedings of Voronezh State University. Series: Geography. Geoecology0, no. 4 (December 9, 2021): 126-134. Accessed December 5, 2025. https://journals.vsu.ru/geo/article/view/3761.