- FondsMordell - Papers of Louis Joel Mordell
- Series1-40 - Letters
- File17 - Mahler
- Item17.1 - T.L.s., in German, from Gottingen
- Item17.2 - T.L.s., from Krefeld
- Item17.3 - T.L.s., from Krefeld
- Item17.4 - T.L.s., from Krefeld
- Item17.5 - T.L.s., from Krefeld
- Item17.6 - T.L.s., from Amsterdam
- Item17.7 - A.L.s., from Amsterdam
- 35 more...