Thos. Agnew & Sons created and maintained various indexes over the course of their history, most of which date to the late 19th-20th centuries. They have been arranged as follows:
NGA27/31/1: Indexes to Pictures
NGA27/31/2: Indexes to Drawings
NGA27/31/3: Indexes to On Sale (Bo/s) Books
NGA27/31/4: Indexes to Private Collectors
NGA27/31/5: Indexes to Specific Collections
NGA27/31/6: Indexes to Photographs and Negatives
NGA27/31/7: Card Indexes (including Card Indexes to Paintings, Watercolours and Drawings, On Sale (Bo/s) artworks, Turner Pictures, Turner Drawings, Exhibitions, Clients, Authours, Subjects, etc)
NGA27/31/8: Indexes to Property at Auctions
NGA27/31/9: Indexes to Waiting Order Books
NGA27/31/10: Indexes to Christie's Stencil Marks
NGA27/31/11: Indexes to Clients