Quantity of the Monster
From Memory Alpha, the free Star Trek reference
"Quantity of the Monster" was a science fiction story written by Herbert Rossoff for the January 1953 issue of Incredible Tales magazine. (DS9: "Far Beyond the Stars")
As an in-joke, this work's title is suspiciously similar to that of Robert Heinlein's science fiction novel The Number of the Beast (which itself contains many in-jokes).
