| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| 1958 |
|
Beyond the Vanishing Point / The Secret of ZI | Ace Books | Omnibus | 5 |
| July 1959 |
|
New Worlds Science Fiction, July 1959 | Nova Publications Ltd. | MAGAZINE | 4 |
| August 1959 |
|
New Worlds Science Fiction, August-September 1959 | Nova Publications Ltd. | MAGAZINE | 75 |
| October 1959 |
|
New Worlds Science Fiction, October 1959 | Nova Publications Ltd. | MAGAZINE | 77 |
| March 1960 |
|
I Romanzi del Cosmo #48 | Ponzoni | MAGAZINE | 3 |
| 1961 |
|
The Secret of ZI | Digit Books | Novel | 5 |
| April 1965 |
|
Freiheit für die Erde | Moewig | Novel | 5 |
| April 1969 |
|
The Patient Dark | Robert Hale | Novel | |
| March 1980 |
|
Freiheit für die Erde | Pabel-Moewig | Novel | 7 |
| September 2011 |
|
The Patient Dark | Gateway / Orion | Novel |