Urban, Thomas (September 1, 2001). "Poszukiwany Hermann Schaper". Rzeczpospolita (in Polish) (204). Archived from the original on November 24, 2007. Retrieved March 11, 2016.
Urban, Thomas (September 1, 2001). "Poszukiwany Hermann Schaper". Rzeczpospolita (in Polish) (204). Archived from the original on November 24, 2007. Retrieved March 11, 2016.