| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| December 1960 |
|
Analog Science Fact -> Fiction, December 1960 | Street & Smith Publications, Inc. | MAGAZINE | 37 |
| April 1961 |
|
Analog Science Fact -> Fiction, April 1961 | Atlas Publishing and Distribution Co. Ltd | MAGAZINE | 35 |
| September 2007 | The K-Factor | Project Gutenberg | Chapbook |