WIA GC/1887/10 | Ruben, Paul to Warburg, Aby 15/10/1887 | mentions Ernst Levy, Wilhelm Kiesselbach, John [Johann Nicolaus] Hertz, Johannes [Hans] Nippen... |
WIA GC/1892/35 | Nirrnheim, Hans; Schultz, Adolf and Kiesselbach, Wilhelm to Warburg, Aby 12/02/1892 | greetings from a pub night; they reassure Warburg about the exams |