1807
National Gallery of Art, 1850
National Gallery of Art, 1980
National Gallery of Art, 1860
National Gallery of Art, 1884
National Gallery of Art, 1927
National Gallery of Art, 1966
National Gallery of Art, 1962
National Gallery of Art, 1700
National Gallery of Art, 1938
National Gallery of Art, 2005
National Gallery of Art, 1977
National Gallery of Art, 1952
![Nilpferdkopf im Profil (Hippo Head) [p. 19]](https://api.nga.gov/iiif/c3aa33e1-6e99-4c90-9d89-04a30b272660/full/843,/0/default.jpg)
![WLS VIII from White Line Squares (Series I) [artist's proof]](https://api.nga.gov/iiif/3fe6f7ec-b458-4bd6-858c-9bd399b9365c/full/843,/0/default.jpg)
