1966
Gemini G.E.L., 1986
Gemini G.E.L., 1968
Gemini G.E.L., 1989
Josef Albers, 1974
Gemini G.E.L., 1981
Gemini G.E.L., 1972
Gemini G.E.L., 1969
Gemini G.E.L., 1992
Josef Albers, 1972
James Webb, 1967
![Figure 3 [trial proof]](https://api.nga.gov/iiif/e68af6c9-d264-485e-8f17-bbfc36dff5fa/full/843,/0/default.jpg)
![Flower Head [special proof]](https://api.nga.gov/iiif/77e40d43-24c5-4c41-b0c3-66617770f4ae/full/843,/0/default.jpg)
![Zone [working proof]](https://api.nga.gov/iiif/1999af7d-aa2f-47f4-b196-48da915e2733/full/843,/0/default.jpg)
![Alphabet [trial proof 2]](https://api.nga.gov/iiif/8b86d47c-dd73-4cc3-8b52-02d368a7462b/full/843,/0/default.jpg)
