The Worlds of J. R. R. Tolkien: The Places That Inspired Middle-earth by John Garth

A comparison of Tolkien's life and the geography of his works. Discusses it from the first Books of Lost Tales when he mapped his fantasy lands directly on England to the final works. Divided up by geographical type, such as the countryside he grew up, forests, and the trip to the Alps that influenced his mountains. Carefully gathers the evidence toward elements being possible or certain influences.