- The story title is stated as "Ad Astra?" with the question mark in Messages Found in an Oxygen Bottle.
- The copyright page for Messages Found in an Oxygen Bottle states
"Ad Astra?" copyright © 1986 by Bob Shaw. First appeared in Vector.
implying it was published in a 1986 issue of Vector. Further research finds that it appeared in the May/June 1973 issue.
| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| May 1973 | Vector 65 | BSFA | MAGAZINE | 38 | |
| 1979 |
|
The Best of the Bushel | Paranoid/Inca Press | Nonfiction | 57 |
| 1986 |
|
Between Two Worlds / Messages Found in an Oxygen Bottle | NESFA Press | Collection | 27|14 |
| 1986 |
|
Between Two Worlds / Messages Found in an Oxygen Bottle | NESFA Press | Collection | 27|14 |