German International. Vol. 16. Illinois: Heinz Moeller-Verlag. 1972. p. 28. Archived from the original on 23 February 2024. Retrieved 6 March 2024 – via Google Books.
Augstein, Rudolf, ed. (10 August 1955), "In König Nordhoffs Reich" [In King Nordhoff's realm], Der Spiegel (in German), vol. 33/1955, p. 16, archived from the original on 21 December 2018, retrieved 23 January 2025, muß luftgekühlt sein, denn nicht jeder Landarzt hat eine Garage
Brosowsky, B. M. (22 July 2016), "Das Schweigen der Autobauer" [The silence of the car manufacturers], Die Tageszeitung, pp. 28 ePaper 23 Nord, archived from the original on 5 December 2023, retrieved 18 February 2024
Augstein, Rudolf, ed. (10 August 1955), "In König Nordhoffs Reich" [In King Nordhoff's realm], Der Spiegel (in German), vol. 33/1955, p. 16, archived from the original on 21 December 2018, retrieved 23 January 2025, muß luftgekühlt sein, denn nicht jeder Landarzt hat eine Garage
Brosowsky, B. M. (22 July 2016), "Das Schweigen der Autobauer" [The silence of the car manufacturers], Die Tageszeitung, pp. 28 ePaper 23 Nord, archived from the original on 5 December 2023, retrieved 18 February 2024
German International. Vol. 16. Illinois: Heinz Moeller-Verlag. 1972. p. 28. Archived from the original on 23 February 2024. Retrieved 6 March 2024 – via Google Books.