Originally published, New York: St. Martins P., 1964; (B67- 3122), London: Dobson, 1966.
OBNB doesn't sell books, but you may be able to find a copy at one of these websites:
Davy by Edgar Pangborn. ISBN 0140026002. Published by Penguin in 1969. Publication and catalogue information, links to buy online and reader comments.