1. University of Pennsylvania, Ms. Codex 1353 DS ID: DS1066 Title: Ledger Author: Niccolo de Medici Place: Italy Date: 1567-1590.
2. University of Pennsylvania, Ms. Codex 1420 DS ID: DS1344 Title: Ledger Author: Bartolomeo di Stefano Place: Italy Date: 1514-1522.