Die Fremden kommen ...

From Author Wars - https://authorwars.com/books/die-fremden-kommen-1813348.html

Overview:

Title: Die Fremden kommen ...
Author: L. Sprague de Camp
Year: 1969
Type: Short Fiction

Editions/Publications:

Unknown. Die Mächtigen des Universums (Unknown, L. Sprague de Camp, Heyne, DM 2.60, 171 pages, Paperback, Anthology)
Unknown. Die Mächtigen des Universums (Unknown, L. Sprague de Camp, Heyne, 171 pages, Paperback, Anthology)