American
Black Stack
TR I
Haystack #4
Haystack #6 (State III)
Casa Cornu
Bonne Bay
Avicenna
Earth Day
, 1970
, 1971
![Hinged Canvas [trial proof]](https://api.nga.gov/iiif/087635d2-317e-400b-9248-17a0efc212b4/full/843,/0/default.jpg)
![Bent "Blue" [working proof]](https://api.nga.gov/iiif/25190e59-6ffb-4652-ab02-8434c9babb59/full/843,/0/default.jpg)
![Hinged Canvas [working proof]](https://api.nga.gov/iiif/5b33088c-1b2c-4997-8976-108b97ca48e8/full/843,/0/default.jpg)
![Hinged Canvas [working proof]](https://api.nga.gov/iiif/a6ae14d2-058f-49b6-bdce-be6cd9b9cd0d/full/843,/0/default.jpg)
![Hinged Canvas [working proof]](https://api.nga.gov/iiif/055e0103-4f55-430d-a6ba-69251020d4d0/full/843,/0/default.jpg)
![Bent "Blue" [trial proof]](https://api.nga.gov/iiif/0897b9bd-7a5c-4315-b3e0-da35c5fc8db7/full/843,/0/default.jpg)
