Milano, Archivio Capitolare, sine numero
Selected Canon Law Collections, ca. 500–1234
Pennington (Bio-Bib Report a242) lists "Milano, Archivio San Ambrogio [No shelfmark]" as a copy of Gratian's Concordia discordantium canonum, but this probably is an erroneous reference to Milano, Archivio Capitolare, M.57.
