The Acknowledgment is both a blend of fiction set in the Lensman universe and an essay thanking people who helped the author though giving them titles or roles set in the Lensman universe.
| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| November 1965 |
|
Second Stage Lensmen | Pyramid Books | Novel | 271 |
| July 1966 |
|
Second Stage Lensmen | Pyramid Books | Novel | 271 |
| November 1967 |
|
Second Stage Lensmen | Pyramid Books | Novel | 271 |
| May 1968 |
|
Second Stage Lensmen | Pyramid Books | Novel | 271 |
| February 1972 |
|
Second Stage Lensmen | Pyramid Books | Novel | 271 |
| October 1972 |
|
Second Stage Lensmen | Pyramid Books | Novel | 271 |
| October 1973 |
|
Second Stage Lensman | Pyramid Books | Novel | |
| January 1975 |
|
Second Stage Lensmen | Pyramid Books | Novel | 271 |
| November 1976 |
|
Second Stage Lensman | Pyramid Books | Novel | 271 |