Here are a few useful links and references that will be helpful throughout the course of this class.
Websites:
ArtnetArtnet
Artprice.com
Arttactic.com
Universes-in-universe.org Artprice
Arttactic
Universes in universe
Auction Houses:
Christie's, New York and London
Phillips De Pury & Company, New York
Sotheby's, New York and London
Swann Galleries, New York
...