Notes: • ©1955 No other statement of publication or printing • Cover art is credited to Savage on the copyright page; no visible signature Year of publication 1971 from ads in the back. There are four printings with the same catalog #/price/cover. Externally they are identical in every way, internally the only difference is the ads in the back. This printing has three pages of ads: 2 with no number "more Ace Science Fiction Specials" and "Jack Vance's Great New World Series; Planet of Adventure" and one numbered 17 "10 Novels By Robert E. Heinlein" [this last one has not been seen so the Heinlein might be 17A with 11 titles].