all on mount: upper left verso, in graphite: 1918 / O'Keeffe / Palladio A+1; all by later hands: upper left verso, in graphite: 1 (in square); lower left verso, in graphite: OK--3C
Georgia O'Keeffe; gift to NGA, 1980.
- Alfred Stieglitz: Known and Unknown, National Gallery of Art, Washington; The Museum of Fine Arts, Houston, 2002-2003, as Georgia O'Keeffe--Feet.
- McCabe, Constance, and Lisha Deming Glinsman. "Understanding Alfred Stieglitz' Platinum and Palladium Prints: Examination by X-ray Fluorescence Spectrometry." Studies in the History of Art 51: Conservation Research 1995 (Washington, 1995), fig.19.
- Greenough 2002, cat. 514.