Petsch, Johann Philipp
| Johann Philipp Petsch an Louis Spohr in Kassel | Frankfurt am Main, Dienstag 20. Juli 1858 | 1858072048 |
| Johann Philipp Petsch an Louis Spohr in Kassel | Frankfurt am Main, Freitag 3. September 1858 | 1858090348 |
| Louis Spohr an Johann Philipp Petsch in Frankfurt am Main | Kassel, Sonntag 1. August 1858 | 1858080118 |