1981–1982
National Gallery of Art, 1838
National Gallery of Art, 1631
National Gallery of Art, 2000
National Gallery of Art, 1522
National Gallery of Art, 1909
National Gallery of Art, 1924
Gemini G.E.L., 1980
National Gallery of Art, 1620
National Gallery of Art, 1592
National Gallery of Art, 1480
National Gallery of Art, 1978
National Gallery of Art, 1834
![Over the River, Project for the Arkansas River, Colorado [bottom panel]](https://api.nga.gov/iiif/0fbb683b-c2b6-4362-ae8c-9e416624c473/full/843,/0/default.jpg)
![Drypoint Zeta [special proof]](https://api.nga.gov/iiif/51358fc0-5cb3-4175-96e9-1b6519a9fc0f/full/843,/0/default.jpg)
