- FondsMordell - Papers of Louis Joel Mordell
- Series1-40 - Letters
- File9 - Hasse
- Item9.1 - A.L.s., in German from Halle
- Item9.2 - T.L.s., from Marburg
- Item9.3 - T.L.s., from Marburg
- Item9.4 - A.P.s., from Marburg
- Item9.5 - A.L.s., from Marburg
- Item9.6 - T.P., from Marburg
- Item9.7 - T.L.s., in German, from Marburg
- 15 more...