LINKS
INTRODUCTION:
The following links provide contacts with specialists, additional information on
relevant topics, and photographs that can be used for reference purposes or
purchase.
ORGANIZATIONS and WEBSITES OF INTEREST:
Smithsonian
Institution National Anthropological Archives (19th c. Native American
photographs, esp. delegations): https://www.si.edu/siasc/naa
Library of
Congress Prints & Photographs Division: https://www.loc.gov/pictures/
London Stereoscopic
Association (publishes 3D books and provides background
information):https://www.londonstereo.com/
PhotoLondon (in-depth information about
19th century London photographers): https://photolondon.org.uk/#/
DEALERS:
Worldofstereoviews (images for sale):
Jefferson Stereoptics (auctions):
NSA 3D conventions,
including Virtual Conventions: https://stereoworld.org/annual-3d-convention/
"...to
promote the research, collection, and use of vintage and contemporary
stereoviews, stereo cameras, equipment, and related materials" 
All
about collecting:stereoscopes, glass and paper stereoviews, View-Master reels,
obscure advertisements and 3D toys.