2007 Christie's Images Limited
akg-images 5001601
akg-images 223155
Courtesy Koller Auktionen, Zürich
Sotheby's Deutschland
Archiv Eigentümer(in) / Owner’s Archive. Foto: Peter Schälchli, Zürich
Board of the Trustees of the University of Illinois on behalf of its Krannert Art Museum University of Illinois. Purchase through the Festival of Arts Purchase fund 1950-2-1