The Thirteenth Treasure

From Author Wars - https://authorwars.com/books/the-thirteenth-treasure-2543795.html

Overview:

Title: The Thirteenth Treasure
Author: Charlotte Hunt
Year: 1972
Type: Novels
Series: Paul Holton
Number in Series: 4

Editions/Publications:

Unknown. The Thirteenth Treasure (Unknown, Charlotte Hunt, Ace Star, $0.95, 252 pages, Paperback, Novel)
Unknown. The Casebook of Dr. Holton: The Lotus Vellum and The Thirteenth Treasure (Unknown, Charlotte Hunt, Ace Books, ISBN-10: 0441091768, $1.95, 630 pages, Paperback, Omnibus)