lower left in graphite: 26/30; lower center in graphite: Plexus; lower right in graphite: SW Hayter
Jacob Kainen, Washington, DC; acquired 2002 by the National Gallery of Art
- Black, Peter, and Désirée Moorhead. The Prints of Stanley William Hayter: A Complete Catalogue. Mount Kisco, New York: Moyer Bell Limited, 1992, no. 399, iii/iii.