1960–1980
National Gallery of Art, 1520
National Gallery of Art, 1630
National Gallery of Art, 1500
National Gallery of Art, 1497
National Gallery of Art, 1862
National Gallery of Art, 1771
National Gallery of Art, 1935
National Gallery of Art, 1939
National Gallery of Art, 1926
National Gallery of Art, 1976
National Gallery of Art, 1924
National Gallery of Art, 1570
![#6 (after 'Untitled 1975') [progressive proof 13]](https://api.nga.gov/iiif/dae4df82-2617-4b76-84ce-da1bf69a5eb4/full/843,/0/default.jpg)
