lower left on stone: Mordi / Gassner / 1936; lower left in graphite: Polar Bear: The Solitudes; lower center in graphite: To Abe - who knows what / Solitude is; lower right in graphite: Mordi Gassner / Oct 26, 1945
Dorothy Gordon Pocinki; by inheritance to her son, Alan Pocinki, Potomac, MD; acquired 2011 by the National Gallery of Art
- Windisch, Gail, and Sylvan Cole, Jr. Art for Every Home: An Illustrated Index of Associated American Artists Prints, Ceramics, and Textile Designs. Manhattan: Marianna Kistler Beach Museum of Art, Kansas State University, 2016, p. 26, no. 151.