1. RP 993 Reference (shelfmark): RP 993 Title: Scope & Content: Various autograph letters Creation dates: 1860 - 1901 Collection Area: Western Manuscripts Languages: English and German Date Range: 31 Jul 1974 Extent: 11 photocopies
2. RP 993/6 Reference (shelfmark): RP 993/6 Title: Scope & Content: A Einstein to Professor Plesch Creation dates: Undated Collection Area: Western Manuscripts Languages: German Date Range: 31 Jul 1974 Extent: photocopies