L. Signorello, “«Questa sie la resone de li libri che se fano del choro di Sancta Maria del Popolo»: Prolegomena to the study of the choir books of Santa Maria del Popolo, gleanings from the documentary sources and a look at two (unpublished) illuminated graduals by the Master of the Barbo Missal”, BI, vol. 12, no. 2, pp. 257–305, Jan. 2023.