Die Anderen, which translates from German to The Sea People, was written by Adam Lukens and published in 1959. My research dug up some interesting trivia about Lukens. According to the Feminist SFF & Utopia website, Adam was a she—Diane Detzer, to be exact, who was born on May 13, 1930, and used the pseudonyms “Adam Lukens” and “Jorge De Reyna.”
She was difficult to trace, but I did manage to find a short list of her works. Whether this is a complete bibliography is uncertain:
* Alien World [Avalon, 1963] as Lukens
* Conquest of Life [Avalon, 1960] as Lukens
* Eevalu [Avalon, 1963] as Lukens
* The Glass Cage [Avalon, 1962] as Lukens
* The Planet of Fear [Avalon, 1968]
* The Return of the Starships [Avalon, 1968] as de Reyna
* The Sea People [Avalon, 1959] as Lukens
* Sons of the Wolf [Avalon, 1961] as Lukens
* The World Within [Avalon, 1962] as Lukens
Not a big surprise to me, since women often resorted to male pseudonyms in order to get published, and women especially weren’t supposed to write sci-fi.
Thanks to Cassie for linking to a whole host of awesome German vintage science fiction covers.