"Der zwölfte Planet"

From Author Wars - https://authorwars.com/books/der-zwolfte-planet-1636708.html

Overview:

Title: "Der zwölfte Planet"
Author: Horst-Günter Rubahn
Year: 1980
Type: Essays

Editions/Publications:

1980 . Perry Rhodan, #980: Schwerkraft-Alarm (1980, Horst-Günter Rubahn, Pabel-Moewig, DM 1.80, 68+xvi pages, digest, MAGAZINE)
1980 . Perry Rhodan, #139: Die Laurins kommen! (1980, Horst-Günter Rubahn, Pabel-Moewig, DM 1.80, 68+xvi pages, digest, MAGAZINE)