| Publisher | Publicações Europa-América |
| Translated by | Maria Freire da Cruz |
| Copyright Holder | Robert A. Heinlein |
| Cover/Jacket Design by | estúdios P. E. A.* |
| Editor | Francisco Lyon de Castro |
| Series | Ficção Científica |
| Printed by | Gráfica Europam, Lda. |
| Format | Paperback |
| Language | Portuguese |
| Location | Portugal |
| Copyright | 1958 |
| Pages / Font | 177 pages |
| Series Number | 33 |
| Edition No. | 35 033/3196 |
Added by Xavier.Rafael