Das große Geheimnis

From Author Wars - https://authorwars.com/books/das-grosse-geheimnis-2000061.html

Overview:

Title: Das große Geheimnis
Author: René Barjavel
Year: 1975
Type: Novels

Editions/Publications:

Unknown. Welten der Zukunft: Chroniken aus Raum und Zeit Band 12 (Unknown, René Barjavel, Heyne, ISBN-10: 3453312813, DM 10.00, 559 pages, Paperback, Omnibus)
Unknown. Das große Geheimnis (Unknown, René Barjavel, Heyne, ISBN-10: 345330327X, DM 4.80, 207 pages, Paperback, Novel)