1840–1899
National Gallery of Art, 1940
National Gallery of Art, 1937
National Gallery of Art, 1599
National Gallery of Art, 1974
National Gallery of Art, 1956
National Gallery of Art, 1884
National Gallery of Art, 1941
National Gallery of Art, 1650
National Gallery of Art, 1971
National Gallery of Art, 1932
National Gallery of Art, 1536
National Gallery of Art, 1645
![Nilpferdkopf mit geöffnetem Maul (Hippo Mouth Open) [p. 27]](https://api.nga.gov/iiif/40890b8f-34f2-4042-a758-055cee939ead/full/843,/0/default.jpg)
![Head of a Young Man [recto]](https://api.nga.gov/iiif/1e840e0e-ecc5-416f-bb8d-a8b02e11f7a3/full/843,/0/default.jpg)
![Untitled [working proof]](https://api.nga.gov/iiif/65ca8ac9-428e-4ed4-8a3b-01a08e22808d/full/843,/0/default.jpg)
