| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| October 1936 |
|
Secret Agent X, October 1936 | Periodical House | MAGAZINE | |
| 1980 |
|
Secret Agent-X: A History | Robert Weinberg | Nonfiction | 19 |
| 1990 | Secret Agent-X | Golden Perils Press & Fading Shadows | Nonfiction | ||
| September 2017 |
|
The Art of the Pulps: An Illustrated History | IDW Publishing | Nonfiction | 180|180.1 |