Secure the Shadow: The Story of Cape Photography from its beginnings to the end of 1870, by Marjorie Bull and Joseph Denfield, Terence McNally, 1970
From data collected it has been possible to compile a Studio Establishment Index, an invaluable work of reference which will enable all types of photographs which show the photographer's name and place of practice to be dated more accurately than has ever before been possible. The inclusion of 34 biographies enhances the full story of the pioneer photographers, many of whom were prominent in professions other than photography.
Date an Old UK Photograph, by Roger F.Vaughan. Extremely useful information, also applicable to South African photographs.
Types of Photographs and their history, by Gary Clark.