"Die tapferen sieben Ulmer" [The brave seven Ulmer] (بالألمانية). SPIEGEL-Verlag. 9 Feb 2007. Archived from the original on 2010-03-29. Retrieved 2011-11-04.
"Die tapferen sieben Ulmer" [The brave seven Ulmer] (بالألمانية). SPIEGEL-Verlag. 9 Feb 2007. Archived from the original on 2010-03-29. Retrieved 2011-11-04.