1974
Gemini G.E.L., 1969
Edward Henderson, 1978
Gemini G.E.L., 1971
Jeff Wasserman, 1972
Gemini G.E.L., 1975
Edward Henderson, 1976
Gemini G.E.L., 1980
Charles Ritt, 1969
![Figure 1 [color trial proof]](https://api.nga.gov/iiif/12239379-e928-4fb3-b6fb-5c8d18956f8a/full/843,/0/default.jpg)
![Ale Cans [trial proof A]](https://api.nga.gov/iiif/29cf464a-4b21-46fc-a6ab-d08362bfb8b4/full/843,/0/default.jpg)
![#3 (after 'Untitled 1975') [trial proof]](https://api.nga.gov/iiif/8169f808-7479-4209-8836-a0235ad6d5d5/full/843,/0/default.jpg)
![Drypoint Delta [special proof]](https://api.nga.gov/iiif/6467a0f7-a7ae-40fc-98b2-b27ea13e71b0/full/843,/0/default.jpg)
![Figure 5 [working proof]](https://api.nga.gov/iiif/e6d60deb-19f5-4b34-baee-8be39d5ea772/full/843,/0/default.jpg)