A breviary from 15th-century Italy, where the rubric for the feast of the Holy Innocents (28 December) on f. 30v in the second column begins, 'In sanctorum innocentium Invitatorium, ymni, antiphone nocturnales, psalmi, versiculi dicuntur de communi plurimorum martirum...' while the readings, proper to the feast, are given in full.
Full Citation
New York, Columbia University, Rare Book and Manuscript Library, Smith Western MS 15, ff. 30v-31r