61. University of Pennsylvania, Ms. Coll. 196 DS ID: DS1757 Title: Letter Author: Piero Vettori Date: 1563-1585.
62. University of Pennsylvania, CAJS Rar Ms 559e DS ID: DS25934 Title: Letter Author: Natan-Noṭe ben David, (Ożarów, Poland) Place: Danzig Date: 12 Elul 5529 (11 January 1769)