Pellucidar

From Author Wars - https://authorwars.com/publications/pellucidar-249246.html

Overview:

Title: Pellucidar
Author: Edgar Rice Burroughs
Year: Unknown
Publisher: Ace Books
Price: $0.95
Pages: 191
Binding: Paperback
Type: Novel
Title Reference: Pellucidar
Notes: Cover not credited but is listed as Frazetta at http://www.erbzine.com/mag7/0742.html#bb and is his style. Copyright page says this is the Second Ace printing, but so does the $0.75 printing. It is at least the 5th printing.