(in German)Der 20. Juli 1944Archived 2019-03-06 at the Wayback Machine, Gedenkstätte Deutscher Widerstand [ Memorial Center of the German Resistance ], Plötzensee, 2003
(in German) Till Mayer, Mein Vater, der verhasste Held [ My Father, the Despised Hero ], Spiegel Online, posted 19 July 2011
web.archive.org
(in German)Der 20. Juli 1944Archived 2019-03-06 at the Wayback Machine, Gedenkstätte Deutscher Widerstand [ Memorial Center of the German Resistance ], Plötzensee, 2003