Alfred Stieglitz: „Songs of the Sky C1“, 1923, 11,5 x 9 m (aus: Sarah Greenough, Alfred Stieglitz. The Key Set. The Alfred Stieglitz Collection of Photographs, Washington. National Gallery of Art, New York: Harry N. Abrams, 2002, Vol. 2: 1923–1937, S. 521)	Fenster schliessen