^ abDetlef Mühlberger, Hitler's Voice: The Völkischer Beobachter, 1920-1933. Organisation & Development of the Nazi Party, Volume 1, Peter Lang, 2004, p. 103
^F.L. Carsten, The Rise of Fascism, London: Methuen & Co, 1974, p. 106
^Jonathan Wright, Gustav Stresemann: Weimar's Greatest Statesman, Oxford University Press, 2004, p. 142
^Hermann Beck, The Fateful Alliance: German Conservatives and Nazis in 1933: The Machtergreifung in a New Light, Berghahn Books, 2009, pp. 36-7
^Douglas G. Morris, Justice Imperiled: The Anti-Nazi Lawyer Max Hirschberg in Weimar Germany, University of Michigan Press, 2005, p. 255