The Nature of Middle-earth by J. R. R. Tolkien, Carl F. Hoste... - 9780008440572

The Real Middle-Earth : A History of the Dark Ages that Inspired Tolkien

Why We Love Middle-earth : An Enthusiast's Book about Tolkien, Middle-earth, and the LotR Fandom (A Middle-earth Treasury)

The Little Book of J.R.R. Tolkien: Wit and Wisdom from the creator of Middle Earth: 11

The Ring Legends of Tolkien: An Illustrated Exploration of Rings in Tolkien's World, and the Sources that Inspired his Work from Myth, Literature and History