Attack from the Unseen

From Author Wars - https://authorwars.com/books/attack-from-the-unseen-904180.html

Overview:

Title: Attack from the Unseen
Author: Clark Darlton
Year: 1974
Type: Short Fiction

Editions/Publications:

Unknown. Perry Rhodan #50: Attack from the Unseen (Unknown, Clark Darlton, Ace Books, $0.95, 164 pages, Paperback, MAGAZINE)