There is some yellowing, but it can be read without any problems. First Edition Breakdown: Volume 3, 5, 7, 8, 9, 10, 11, 12, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27 22 out of 27 volumes are first editions, making them rare.