1. University of Pennsylvania, Ms. Codex 463 DS ID: DS30276 Title: Letter Author: Cosimo I de' Medici, Grand Duke of Tuscany Place: Italy Date: 1600?
2. Newberry Library, VAULT folio Case MS 5170 DS ID: DS17716 Title: Letter Author: Francesco I de' Medici Place: Italy and Ferrara Date: 1559 [that is, 1560] Feb. 22.