- FondsMordell - Papers of Louis Joel Mordell
- Series1-40 - Letters
- File6 - Erdos
- File6.1 - Letters
- 41 more...
- Item6.1.42 - A.L.s., from University of Pennsylvania
- Item6.1.43 - A.L.s., from University of Pennsylvania
- Item6.1.44 - A.L.s.
- Item6.1.45 - A.L.s., from Philadelphia
- Item6.1.46 - A.L.s.
- Item6.1.47 - T.L.s.
- Item6.1.48 - A.L.s.
- Item6.1.49 - A.L.s., from Syracuse, New York
- Item6.1.50 - A.L.s., and typed copy
- 2 more...