lower left in plate: PEIRCE; lower center: MARIA PICCOLOMINI.
- Foster, Allen Evarts. "A check list of illustrations by Winslow Homer in 'Harper's Weekly' and other periodicals." Bulletin of the New York Public Library 40 (1936): 842-852. Separately published New York: New York Public Library, 1936.
- Gelman 1969, no.53.
- Kelsey 1977, no.42.