Edgar Rice Burroughs (2015). “TARZAN OF THE APES SERIES (Illustrated): Tarzan of the Apes, The Return of Tarzan, The Beasts of Tarzan, The Son of Tarzan, Tarzan and the Jewels of Opar, Jungle Tales of Tarzan, Tarzan the Untamed and Tarzan the Terrible”, p.49, e-artnow