The History of Middle-Earth, is a series compound by twelve volumes, published in 1983 to 1996, that analyze the works of J.R.R. Tolkien. The book was edited and compiled by his son, Christopher Tolkien. These books are extremely detailed, Christopher Tolkien wrote the books based the annotations of his father. But some texts continue not published, they continue in the libraries of Bodleian and Marquette University, and in particular hands, like in "Elvish Linguistic Fellowship".