Source: Praha, Knihovna Národního muzea, ms. XII A 1Siglum: CZ–Pn XII A 1Folios: 118v-120rFolio: 118vFull text (or incipit): Natus ante seculaGenre: SqRubrics: ProsaRubrics2: ad missam iiiam (117r)Feast: Nativitas DominiCantus ID: ah15015 Form: M