Siva!

From Author Wars - https://authorwars.com/publications/siva-283225.html

Overview:

Title: Siva!
Author: Leigh Richmond, Walt Richmond
Year: 1979
ISBN-10: 0441768369
Publisher: Ace Books
Price: $1.95
Pages: xv+172
Binding: Paperback
Type: Novel
Title Reference: Siva!
Notes:
"This Ace printing: May 1979"; no number line
"Originally published as "The Lost Millennium"" on copyright page
Cover art by Steve Fabian on copyright page, the initials SF are on the artwork