来源
The artist's estate.
Roman Norbert Ketterer, Stuttgart, by whom acquired from the above.
Anonymous sale, Auktionshaus Arnold, Frankfurt, 1 June 2002, lot 10.
Galerie Rosenbach, Hanover.
Anonymous sale, Grisebach, Berlin, 12 June 2004, lot 179.
Acquired at the above sale by the present owner.