Notes: From Locus1: This is a special 40th anniversary edition, a signed, numbered, slipcased limited edition of 1,500 copies. This is a facsimile edition, but the book is the size of current Doubleday books rather than the 1950 size, there is some color variation on the cover, and the logo has been redone. There is an enclosed pamphlet with a new Asimov introduction and an editor's note by Jennifer Brehl.