Vaihinger an Kurd Laßwitz, Halle, 11.8.1897, 1 S., hs., Postkarte an Herrn | Professor Dr Lasswitz | Gotha, Poststempel HALLE | 11.8.97 | 1-2 N | * (SAALE) 4 [...]. Halle (Saale), 11/08/1897