Back to the Stone Age

From Author Wars - https://authorwars.com/publications/back-to-the-stone-age-855642.html

Overview:

Title: Back to the Stone Age
Author: Edgar Rice Burroughs
Year: Unknown
ISBN-10: 0441046363
Publisher: Ace Books
Price: $1.95
Pages: 251
Binding: Paperback
Type: Novel
Title Reference: Back to the Stone Age
Notes: "Fourth Ace printing: January 1973", although based on the price, ads and ISBN, this is not the fourth printing. Address: 1120 Ave of the Amvericas Charter, Grosset & Dunlap. Ads are 73 and 15L. "Cover painting by Frank Frazetta", the artwork is also signed