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
- Rockne Krebs: A Retrospective of Drawings, 1965-1982, Baxter Art Gallery, California Institute of Technology, Pasadena; Corcoran Gallery of Art, Washington, DC; Contemporary Arts Center, Cincinnati, Ohio, 1983-1984, no. 5
- 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.