Schönherr, Maximilian (5 July 2020). "Der Reichstag vor Hitler" [The Reichstag before Hitler]. SWR2 (in German). Retrieved 28 April 2022.
"Tumulte und Streit um "Katholikenhetze"" [Tumult and Controversy over "Incitement against Catholics"]. SWR2 (in German). 15 February 2021. Retrieved 28 April 2022.