| Author | Isaac Asimov |
| Publisher | Publicações Europa-América |
| Translated by | José Teixeira de Aguilar |
| Cover/Jacket Design by | Estúdios P. E. A. |
| Cover Art by | Rui Ligeiro |
| Editor | Francisco Lyon de Castro |
| Copyright Holder (Original Edition) | Nightfall, Inc. |
| Publisher Series | Nébula |
| Printed by | Gráfica Europam, Lda. |
| Series | Robot |
| Format | Paperback |
| Language | Portuguese |
| Location | Portugal |
| Pages / Font | 331 pages |
| Edition No. | 41 603/3538 |
| Series Number | 3 |