Auctions
Listed are those auction houses with websites that include illustrated records of works sold and to be sold.
Sotheby's
Christie's
Bassenge, Berlin
Bonhams Auctioneers, London
Bonhams & Butterfields Auctioneers, San Francisco
Dorotheum, Vienna
Glerum Auctioneers, Amsterdam
Galerie Heinemann, München (1872-1939)
Lot-tissimo Auktionsportal
Van Ham Kunst Auktionen, Köln