The Land of Hidden Men

From Author Wars - https://authorwars.com/publications/the-land-of-hidden-men-248810.html

Overview:

Title: The Land of Hidden Men
Author: Edgar Rice Burroughs
Year: Unknown
Publisher: Ace Books
Price: $0.95
Pages: 217
Binding: Paperback
Type: Novel
Title Reference: The Land of Hidden Men
Notes: Copyright page says "First Ace printing: October 1963. Second Ace printing: November 1969. Third Ace printing: January 1973.", same as 47012, making this the 4th printing. "Cover painting by Frank Frazetta", signed.