The link below will take you to an image of a booklet published in 1962 by the San Antonio, Texas Public Library called THE ESSENCE OF CREATIVE WRITING. The booklet consists of "Letters to A Young Aspiring Writer", sent by Ray Bradbury to a student at Rice University. It is not known how many copies of this booklet were issued, but there cannot have been that many as it is very scarce:

IMG_0789.jpg (61 Kb, 5 downloads)