The Mercenary

From Author Wars - https://authorwars.com/publications/the-mercenary-282338.html

Overview:

Title: The Mercenary
Author: Jerry Pournelle
Year: Unknown
ISBN-10: 067183293X
Publisher: Pocket Books
Price: $1.95
Pages: 223
Binding: Paperback
Type: Novel
Title Reference: The Mercenary
Notes:
5th printing as per number line.
There's a listing that matches this pub in Locus #233 (May 1980), giving a publication date of April 1980. It doesn't state if it's the fifth or sixth printing.