Who?

From Author Wars - https://authorwars.com/publications/who-231433.html

Overview:

Title: Who?
Author: Algis Budrys
Year: 1964
Publisher: Penguin Books
Price: 3/6
Pages: 159
Binding: Paperback
Type: Novel
Title Reference: Who?
Notes:
"Published in Penguin Books 1964" Printing not stated, no number line The cover shows a detail from Schakels (1934) by Raoul Hynckes, at the Museum Boijmans van Beuningen in Rotterdam. The painting is incorrectly identified on the book's back cover as "Nature morte".