This document summarizes online resources for researching auction sales and sellers of artworks, including: 1) Auction catalogs from the 1700s to present in the Watsonline and Art Sales Catalogues Online databases, providing bibliographic and full-text records. 2) The SCIPIO database containing over 300,000 auction catalog citations from the 1500s to present. 3) Indexes like ArtNet, AskART, and Art Fact Pro providing information on recent auction sales. 4) Newspaper archives like the Times Digital Archive and New York Times to research past owners and auction sales.