1. Boston Public Library, MS pb Med.170 DS ID: DS3385 Title: Gradual Author: Catholic Church Place: Bologna Date: ca. 1275
2. Free Library of Philadelphia, Lewis E M 42:16-16A DS ID: DS5300 Title: Gradual Place: England Date: 1240-1260
3. Free Library of Philadelphia, Lewis E M 74:7A DS ID: DS5697 Title: Gradual Place: TuscanyFlorenceItaly Date: 1290-1310