| March 11, 2023 | Edited by Gustav-Landauer-Bibliothek Witten | links |
| March 11, 2023 | Edited by Gustav-Landauer-Bibliothek Witten | Added new photo |
| October 23, 2021 | Edited by Gustav-Landauer-Bibliothek Witten | bio, VIAF |
| July 27, 2018 | Created by Gustav-Landauer-Bibliothek Witten | 1st version |
Last edited by Gustav-Landauer-Bibliothek Witten
March 11, 2023 | History