| 
 Details supplied by Larry Estep. | 
| 
 Details supplied by John Locke from Table of Contents. |   | 
| 
 Details supplied by John Locke from Table of Contents. |   | 
| 
 Details supplied by Larry Estep. | 
| 
 Details supplied by John Locke from Table of Contents. |   | 
| 
 Details supplied by Denny Lien. |   | 
| 
 Details taken from online listing. |   | 
| 
 Details supplied by Rick Hall. |   | 
| 
 Details supplied by Rick Hall. |   | 
| 
 Details supplied by Rick Hall. |   | 
| 
 For the first couple of years the magazine was actually titled Secret Agent “X” but in November 1935 it settled down to Secret Agent X by which title it is generally known. | 
| 
 |   |