Publication date from starred review by Kirkus (see the parent novella).
Title page undated --library records imply as "[1968]".
Cover image from Amazon.com ASIN B0006BU7NI, 2018-06-27 as "Buy New $900.00", replaced 2023-05-07 by superior image from the same source, apparently the same publication (now as Hardcover, 1968, "Buy used: $20.43", and ISBN 0394916018).
Cover artist of this 1st ed. is presumed to be interior illustrator Cober.
