Weird Encyclopedia
http://http://www.weird-encyclopedia.com/King-Solomons-Mines.php
Website which lists the historical and literary references to the possibly real diamond mines of King Solomon.
The Literature Network: H. Rider Haggard
http://www.online-literature.com/h-rider-haggard/
General literary website containing a section devoted to Haggard's life and works.
IOBA Standard: Collecting Lost Race Novels
http://www.ioba.org/newsletter/archive/v9/LostWorldBks-Jessica-10-02.html
Bookseller site which includes an article on Haggard's "lost race" novels and others following the same pattern.