The Burroughs Cyclopedia by Clark A. Brady (1996)

I didn't really read this, just took a look, but thought it was interesting to find a reference book on Burroughs. The subtitle is: Characters, Places, Fauna, Flora, Technologies, Languages, ideas and Terminologies Found in the Works of Edgar Rice Burroughs. I looked up a few of the things I had questions about from Princess of Mars and found them informative.