Berserker's Planet

From Author Wars - https://authorwars.com/publications/berserkers-planet-312427.html

Overview:

Title: Berserker's Planet
Author: Fred Saberhagen
Year: Unknown
ISBN-10: 0441054080
Publisher: Ace Books
Price: $2.25
Pages: 233
Binding: Paperback
Type: Novel
Title Reference: Berserker's Planet
Notes: First Ace printing May 1980. 2nd printing per numberline. Cover artist not credited in book. Signature "Boris ©79" at bottom left front cover. Thus Boris Vallejo. There are two main differences from the first printing: Ace's address changed from Park Ave. to Madison Ave and the ads are different Latest book shown in the ads was published November 1980, so likely this printing is late '80/very early '81