Talbot, The Pencil of Nature, pl. XX, variant Gray, Ollman and McCusker, First Photographs: William Henry Fox Talbot and the Birth of Photography, p. 82, variant
before February 1845 Unique photogenic drawing negative. 6 3/4 x 8 3/4 in. (17.1 x 22.2 cm) Numbered '20' in an unidentified hand in ink on the mount; annotated 'LA20' in an unidentified hand in ink on the reverse of the mount.