[5] In 1993 actors Michelle Stafford, Sisu Raiken, Jim Meskimen, Christopher Smith and Tait Ruppert performed segments from the book with Interplay, their improv comedy organization.

[7] Reviewing the Shasta edition, L. Sprague de Camp concluded that the novel was "a rattling good adventure story," its technical flaws outweighed by "the express-train speed of the action [and] the bounce, zest, and exuberant humor.

[9] In a 1986 article in The Washington Post, journalist Janrae Frank commented on L. Ron Hubbard's writings, "Much of his best work of the '40s and '50s, Fear, Slaves of Sleep, Typewriter in the Sky, is written in exactly the same style and won reader polls at the time.

Green of the Chicago Sun-Times noted, "L. Ron Hubbard's Slaves of Sleep/Masters of Sleep (Bridge, $18.95) reprints two short novels on the borderline between fantasy and horror.

"[14] San Francisco Chronicle reported in 2003 that writer John Baxter retained a first edition copy of Slaves of Sleep in his private collection of rare books.