The Dune Encyclopedia

From Author Wars - https://authorwars.com/publications/the-dune-encyclopedia-38930.html

Overview:

Title: The Dune Encyclopedia
Author: Willis E. McNelly
Year: 1984
ISBN-10: 0425068137
Publisher: Berkley Books
Price: $9.95
Pages: ix+526
Binding: Trade Paperback
Type: Non-fiction
Title Reference: The Dune Encyclopedia
Notes:
"Berkley trade paperback edition/June 1984" No printer's key. Price on front cover and spine. ISBN on the copyright page. C$11.95 in Canada. Published a month before the Putnam hardcover edition. Though not credited the cover art is obviously by Vincent DiFate No LCCN found from LoC catalog search.