Friedrich, Gerhard
| Louis Spohr an Wilhelm Speyer in Offenbach | Kassel, Mittwoch 9. November 1831 | 1831110902 |
| Louis Spohr an Wilhelm Speyer in Offenbach | Kassel, Montag 5. Dezember 1831 | 1831120502 |
| Louis Spohr an Wilhelm Speyer in Offenbach | Kassel, Mittwoch 9. November 1831 | 1831110902 |
| Louis Spohr an Wilhelm Speyer in Offenbach | Kassel, Montag 5. Dezember 1831 | 1831120502 |