Who?

From Author Wars - https://authorwars.com/publications/who-580379.html

Overview:

Title: Who?
Author: Algis Budrys
Year: 1975
ISBN-10: 0345245695
Publisher: Ballantine Books
Price: C$1.50
Pages: 185
Binding: Paperback
Type: Novel
Title Reference: Who?
Notes:
• "First Printing: August, 1975"; no number line • "Cover art by Bob Giusti" on the copyright page, the artwork is also signed • Cover printed in the US, book in Canada