„The Coming Phase”. Flight Magazine. 23. 9. 1943. Приступљено 20. 10. 2010. „'This vast industrial area, which has been called by the Germans the "second Ruhr" (and which includes the Southern regions of Germany, the plateau of Bohemia, and Polish Silesia, hitherto more or less impervious to bomber attack), has been stripped of its geographic defenses.'”
