1939
National Gallery of Art, 1490
United States Government, 1935
United States Government, 1937
National Gallery of Art, 1940
United States Government, 1939
National Gallery of Art, 1939
National Gallery of Art, 1938
United States Government, 1938
National Gallery of Art, 1820
![The Mass of Saint Gregory [recto]](https://api.nga.gov/iiif/4d23fcb3-6c20-4387-b54f-a89d717bd134/full/843,/0/default.jpg)
![An Ascending Spiral of Figures [recto]](https://api.nga.gov/iiif/4b46b349-c6de-4c90-bf14-394ac054be51/full/843,/0/default.jpg)
