Originally published: New York: Doubleday, 1950. First published in Great Britain by Dobson Books Ltd, 1967.
"The story entitled 'Robbie' was first published as 'Strange playfellow' in Super science stories, Fictioneers, Inc., ©1940. The following stories from Astounding science fiction, 'Reason', 'Liar!', 'Runaround', 'Catch the rabbit', 'Escape', 'Evidence', 'Little lost robot', 'The evitable conflict', by Street and Smith Publications, inc., ©1941, 1941, 1942, 1944, 1945, 1946, 1947, 1950"--Title page verso.