| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| May 1960 |
|
New Worlds Science Fiction, May 1960 | Nova Publications Ltd. | MAGAZINE | 39 |
| 1965 |
|
To Worlds Beyond | Chilton | Collection | 101 |
| September 1966 | To Worlds Beyond | Chilton | Collection | 101 | |
| June 1969 |
|
To Worlds Beyond | Sphere | Collection | 99 |
| 1971 |
|
To the Stars: Eight Stories of Science Fiction | Hawthorn Books | Anthology | 69 |
| March 1972 |
|
The Reality Trip and Other Implausibilities | Ballantine Books | Collection | 90 |
| March 1972 |
|
The Reality Trip and Other Implausibilities | Ballantine Books | Collection | 90 |
| April 1980 |
|
Invaders from Earth and To Worlds Beyond | Ace Books | Omnibus | 325 |
| July 1996 |
|
The Road to Nightfall | Voyager / HarperCollins | Collection | 330 |
| November 2006 |
|
To Be Continued | Subterranean Press | Collection | 327 |
| November 2006 | To Be Continued | Subterranean Press | Collection | ||
| January 2011 |
|
To Be Continued | Subterranean Press | Collection | |
| September 2011 |
|
To Be Continued | Gateway / Orion | Collection | |
| March 2012 |
|
To Be Continued | Subterranean Press | Collection | 327 |
| May 2016 |
|
The Robert Silverberg Science Fiction Megapack | Wildside Press | Collection | |
| July 2016 |
|
The Robert Silverberg Science Fiction Megapack | Wildside Press | Collection | |
| February 2025 |
|
Black Infinity #11, 2025 | Rocket Science Books | MAGAZINE | 90 |