Ace Books began publishing genre fiction in 1952. Initially these were mostly in the tête-bêche (double) format, but they also published a few single volumes in the early years. The tête-bêche format was discarded in 1973, with later doubles being published adjacent to each other. Between 1952 and 1968, the books had a letter-series identifier; and after that date they were given five-digit numeric serial numbers. Ace stopped publishing its doubles series sometime around 1978.
Number in series: D-517This Russian collection of Rim Worlds stories comprises the novellas The Rim of Space, Bring Back Yesterday, Catch the Star Winds and Space Mercenaries, along with the Beyond the Galactic Rim (collection) and the short story "Zoological Specimen."
The stories in Beyond the Galactic Rim are: 'Forbidden Planet,' 'The Key,' 'Wet Paint' and 'The Man Who Couldn't Stop.'
Moscow : ACT , 2003 pg. 87-217