Graham Reynolds with the assistance of Katharine Baetjer. European Miniatures in The Metropolitan Museum of Art. Exh. cat., The Metropolitan Museum of Art. New York, 1996, pp. 14, 168, 170, no. 214, colorpl. 214 and ill. p. 169, note that the signature is in the same form as that on a work by Hartmann exhibited in Munich in 1912.