Leo <I., Papst>: Liber sermonum sancti leonis primi pape doctoris floridissimi ac eloquentissimi incipit feliciter ... [Basel] : [Wenssler]: [1474]. Universitätsbibliothek Mainz, https://nbn-resolving.org/urn:nbn:de:hebis:77-vcol-1608 / Public Domain Mark 1.0