Baden-Baden, Museum Frieder Burda
Photograph Courtesy of Sotheby's, Inc. © 2002
Städel Museum, Frankfurt am Main - U. Edelmann / ARTOTHEK
Courtesy Hauser & Wirth Collection Services
Washington D. C., Smithsonian Institution, Hirshorn Museum and Sculpture Garden. Gift of the Joseph H. Hirshhorn Foundation, 1966. Foto: Lee Stalsworth