"Although he was best known for his fantasy and science fiction stories, Hubbard wrote in a wide variety of genres, including adventure fiction, aviation, travel, mysteries, westerns and even romance.[67] Hubbard knew and associated with writers such as Isaac Asimov, Robert A. Heinlein, L. Sprague de Camp and A. E. van Vogt.[68] His first full-length novel, Buckskin Brigades, was published in 1937." . . . . . .