lower left in graphite: Heizer GEMINI I 78
- Gemini G.E.L.: Art and Collaboration, National Gallery of Art, Washington, DC; Seattle Art Museum; The Nelson-Atkins Museum of Art, Kansas City; Terra Museum of American Art, Evanston; Los Angeles County Museum of Art; National Museum of Art, Osaka; Yonago City Museum; Michida City Museum of Graphic Arts, 11 July 1985 - 19 March 1989.
- The Serial Impulse at Gemini G.E.L., National Gallery of Art, Washington; Los Angeles County Museum of Art, 2015.
- GEM 825.