Vorhof der Unterwelt

From Author Wars - https://authorwars.com/books/vorhof-der-unterwelt-1811465.html

Overview:

Title: Vorhof der Unterwelt
Author: Paul Alfred Müller
Year: 1960
Type: Novels
Series: Sun Koh Abenteuer (Fix-ups)
Number in Series: 32

Variant Titles:

1960. Vorhof der Unterwelt