- FondsPP - Helen Martens fonds
- Series4 - Felix Mendelssohn research
- 6493 - Untitled
- 58 more...
- File59 - Research on Therese Schlesinger-Devrient
- File60 - Notes on Mendelssohn letters
- File61 - Research on Mendelssohn and Bärmann
- File62 - Annotated photocopy of biography on Mendelssohn by A. Reissmann
- File63 - Research on Mendelssohn’s search for a libretti
- File64 - Photocopies of transcribed letters by Mendelssohn
- File65 - Photocopy of article on Mendelssohn by Emil Naumann
- File66 - Photocopy of transcribed letters from Mendelssohn to Moscheles
- File67 - Photocopies of transcribed letters from Mendelssohn
- 8 more...