At the Earth's Core

From Author Wars - https://authorwars.com/publications/at-the-earths-core-3271.html

Overview:

Title: At the Earth's Core
Author: Edgar Rice Burroughs
Year: 1963
Publisher: Ace Books
Price: $0.40
Pages: 142
Binding: Paperback
Type: Novel
Title Reference: At the Earth's Core
Notes:
"This Ace edition follows the text of the hard-cover book edition, originally published in 1922" - from copyright page "Complete & Unabridged" on the cover Cover art and title page illustration credited to Krenkel on the copyright page Address for publisher is 1120 Avenue of the Americas which puts the date in December at the absolute earliest. An ad at end of book is for 18 ERB titles, from F-156 to F-204 which may put the date as late as May 1963.