Carpenter, Humphrey, ed. The Letters of J. R. R. Tolkien. London: Allen & Unwin, 1981. Carpenter presents a generous selection of all or parts of some 354 of Tolkien's letters. The letters of late 1938 and early 1939 mention his plans to write a sequel to Farmer Giles of Ham and perhaps some three or four other stories of the Little Kingdom. In a letter of 1947 Tolkien denies that Farmer Giles of Ham was written for children and emphasizes that it is "specially composed for reading aloud." This book is indispensable for revealing important observations made by the author on his own work.
——. Tolkien: A Biography......