Author's Afterword: Whirligig World

From Author Wars - https://authorwars.com/books/authors-afterword-whirligig-world-1147852.html

Overview:

Title: Author's Afterword: Whirligig World
Author: Hal Clement
Year: 1953
Type: Essays

Editions/Publications:

Unknown. Mission of Gravity (Unknown, Hal Clement, Del Rey / Ballantine, ISBN-10: 0345316223, $2.75, 233 pages, Paperback, Novel)