Zaitseva, N.A., Korneevets, V.S., Kropinova, E.G., Kuznetsova, T.Y. and Semenova, L.V. 2016. Cross-border Movement of People between Russia and Poland and Their Influence on the Economy of Border Regions. International Journal of Economics and Financial Issues. 6, 4 (Oct. 2016), 1690–1695.