1. The Statement by the President of the Russian Federation V.V. Putin at the plenary meeting of the St. Petersburg International Economic Forum on June 7, 2019. http://kremlin.ru/events/president/news/60707.
2. Materials for the General Plan for the Development of the National Economy of the Siberian Krai (Sibkraiizdat, Novosibirsk, 1930) [in Russian].
3. B. P. Veinberg, “The position of the center of the surface of Russia from the beginning of the Principality of Moscow to the present,” Izv. Imp. Russ. Geogr. O-va. 51 (6), 365–408 (1915).
4. O. Ignatova, “Rosstat named the regions with the largest population decline.” https://rg.ru/2020/02/02/reg-pfo/v-rosstate-nazvali-regiony-s-samoj-bolshoj-ubyliu-naseleniia.html.
5. B. L. Lavrovskii, E. A. Goryushkina, and E. A. Shil’tsin, Regional Imbalances: Russia and Siberia, Ed. by V. I. Suslov (Novosib. Gos. Tekh. Univ., Novosibirsk, 2010) [in Russian].