lower left in graphite: "The Last Trumpet"; lower right in graphite: Boris Artzybasheff
- Czestochowski, Joseph S. James Swann: In Quest of a Printmaker, with Presentation Prints of the Chicago Society of Etchers, Prairie Print Makers, and the Woodcut Society. Iowa: Cedar Rapids Museum of Art, 1990, appendix C, pp. 142-143, no. 12.