"Banks, Edward". Edward Banks in General German Biography (ADB). Allgemeine Deutsche Biographie. Duncker & Humblot. 18 Feb 2013. p. 41. Retrieved 16 March 2018.
"Sieveking, Karl". Karl Sieveking in General German Biography (ADB). Allgemeine Deutsche Biographie. Duncker & Humblot. 4 May 2008. p. 227. Retrieved 16 March 2018.