1967
National Gallery of Art, 1490
National Gallery of Art, 1808
National Gallery of Art, 1420
National Gallery of Art, 1901
National Gallery of Art, 1887
National Gallery of Art, 1893
National Gallery of Art, 1925
National Gallery of Art, 1956
National Gallery of Art, 1954
Corcoran Gallery of Art, 1841
National Gallery of Art, 1936
National Gallery of Art, 1622
![The Mass of Saint Gregory [recto]](https://api.nga.gov/iiif/4d23fcb3-6c20-4387-b54f-a89d717bd134/full/843,/0/default.jpg)
