These sites are recommended for further exploration of photography

Graphics Atlas: http://www.graphicsatlas.org/
A particularly rich and dynamic site. A useful tool for identifying photo types.

Lacey Prpic Hedtke: http://www.laceyprpichedtke.com/
A photographer working in nineteenth-century photo processes in Minneapolis, MN.

The Library of Nineteenth-Century Photography: http://www.19thcenturyphotos.com/
"The majority of the scans in the library are taken from photographs in the collection of Paul Frecker, a London-based dealer in nineteenth-century photography. The primary focus of his collection is British and European cartes-de-visite and cabinet cards, particularly portraiture and anything reflecting his taste for the odd, the quirky and the unusual."