At the Earth's Core

From Author Wars - https://authorwars.com/publications/at-the-earths-core-248472.html

Overview:

Title: At the Earth's Core
Author: Edgar Rice Burroughs
Year: 1976
Publisher: Ace Books
Price: $1.75
Pages: 210
Binding: Paperback
Type: Novel
Title Reference: At the Earth's Core
Notes:
Movie tie-in edition On spine: 441 above 03325 which can infer the ISBN 0-441-03325-3 No cover artist credited, but the poster is signed; artist is credited here Back cover includes stills from the movie which was released July 1976, so the book was likely published at the same time or at most a month later