| Author | Isaac Asimov |
| Copyright Holder | Isaac Asimov |
| Publisher Series | Panther Science Fiction |
| Publisher | Panther, Panther Books Ltd, Granada Publishing Limited |
| Imprint | Panther Books |
| Printed by | C. Nicholls & Company Ltd |
| Series | Multivac, Robot |
| Format | Paperback |
| Language | English |
| Location | UK |
| Copyright | 1969 |
| This Edition Published | 1971 |
| Reprinted | 1972 |
| Reprinted | 1973 |
| Pages / Font | 192 pages / Linotype Plantin |
| Other | 0 586 03657 1 |
| Price | 30p U.K. |
| Price | $1.00 Australia & New Zealand |