The Door Into Summer

From Author Wars - https://authorwars.com/publications/the-door-into-summer-87505.html

Overview:

Title: The Door Into Summer
Author: Robert A. Heinlein
Year: 1977
ISBN-10: 0330025163
Publisher: Pan Books
Price: £0.60
Pages: 190
Binding: Paperback
Type: Novel
Title Reference: The Door Into Summer
Notes:
• "This edition published 1970 by Pan Books Ltd" • "3rd printing 1977"; month from Locus #205 (October 1977); no number line • The artist is not credited, no visible signature on the artwork [original is shown with other D'Achille covers here] • UK 60p, Australia $1.75, New Zealand $1.85