Богданова, Лидия Петровна, and Анна Сергеевна Щукина. 2019. “Tver Region: Information Base and Direction of the Study of Migration Processes”. HERALD OF TVER STATE UNIVERSITY. SERIES: GEOGRAPHY AND GEOECOLOGY, no. 2 (February):33-45. https://journal.tversu.ru/index.php/geo/article/view/171.