upper left in red colored pencil over graphite: "Aleph²"; upper left in graphite: (squared); upper right in graphite (vertically): Gallery 65 Corcoran Scale 1/2"=1'; lower right in graphite: R Krebs / 4/69
the artist, Washington, DC;Corcoran Gallery of Art, Washington, DC, 1974; acquired 2015 by the National Gallery of Art
- Simmons, Linda Crocker and with the assistance of Adrianne J. Humphrey, et al. American Drawings, Watercolors, Pastels, and Collages in the Collection of the Corcoran Gallery of Art. Washington, DC: Corcoran Gallery of Art, 1983: p. 254, no. 1683.