Смирнов, И. П., and О. Т. Умаров. “Socio-Economic Situation in Single-Industry Towns Central Federal District”. HERALD OF TVER STATE UNIVERSITY. SERIES: GEOGRAPHY AND GEOECOLOGY, no. 4, Feb. 2019, pp. 82-95, https://journal.tversu.ru/index.php/geo/article/view/101.