After the end of World War II, the Soviet Union kept most of the territories it occupied in 1939, while territories with an area of 21,275 square kilometers with 1.5 million inhabitants were returned to communist-controlled Poland, notably the areas near Białystok and Przemyśl.U.S. Bureau of the Census The Population of Poland Ed. W. Parker Mauldin, Washington- 1954 P.140 In 1944–1947, over a million Poles were resettled from the annexed territories into Poland (mostly into the Regained Territories). "Przesiedlenie ludności polskiej z Kresów Wschodnich do Polski 1944–1947. Wybór dokumentów", Wybór, opracowanie i redakcja dokumentów: Stanisław Ciesielski; Wstęp: Włodzimierz Borodziej, Stanisław Ciesielski, Jerzy Kochanowski Dokumenty zebrali: Włodzimierz Borodziej, Ingo Eser, Stanisław Jankowiak, Jerzy Kochanowski, Claudia Kraft, Witold Stankowski, Katrin Steffen; Wydawnictwo NERITON, Warszawa 2000
