Oscar Hainauer [d. 1894], Berlin; his wife, Julie Hainauer, Berlin; acquired 1906 by (Duveen Brothers, Inc., London, New York, and Paris); by exchange 21 October 1920 to Joseph E. Widener, Lynnewood Hall, Elkins Park, Pennsylvania; gift 1942 to NGA.
- Bode, Wilhelm von, ed. Die Sammlung Oscar Hainauer / The Collection of Oscar Hainauer. [bound as one volume, English and German pages interleaved in one page sequence] Berlin, 1897 and London, 1906: 93, no. 203 (plaquette no. 63), as style of Donatello.
- A Cabinet of One Hundred & Thirty-Three Bronze Plaques and Medals of the Renaissance Period from the Collection of the Late Herr Oscar Hainauer of Berlin. Ed. Duveen Brothers. London, n.d. (but 1908): no. 94, repro., as style of Donatello.
- Works of Art from the Widener Collection. Foreword by David Finley and John Walker. National Gallery of Art, Washington, 1942: 15.
- Dempsey, Charles. “Lorenzo’s Ombra.” In Lorenzo il Magnifico e il suo mondo. Gian Carlo Garfagnini, ed. Florence, 1994: 341–355, esp. 349, note 28, fig. 6, tentatively attributed to Bartolomeo Bellano, before 1471.
- Barstow, Kurtis. "'The Gualenghi-d'Este Hours': Art and Devotion in Renaissance Ferrara." Ph.D dissertation, University of California, Berkeley, 1997: viii, 22-23, 213 fig. I.10.
- Rossi, Francesco. La collezione Mario Scaglia: placchette. 3 vols. Bergamo, 2011: 1:81, under Prototipo, C.11, as by the circle of Cristoforo di Geremia, and as part of the Hainauer Collection,