- ·Cactus, study
- ·1975
- ·43 cm
- ·Ink, paper
- ·00.163.9.
- ·Cactus, study
- ·1974
- ·42 cm
- ·Ink, paper
- ·00.280.14.
- ·Cactuses, study
- ·1971
- ·52 cm
- ·Ink, paper
- ·00.161.10.
- ·Cactuses, study
- ·1974
- ·43 cm
- ·Ink, paper
- ·00.163.3.
- ·Cactus, study
- ·1974
- ·51 cm
- ·Ink, paper
- ·00.280.18.
- ·Cactus, study
- ·1974
- ·40 cm
- ·Ink, paper
- ·00.162.3.