| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| 1951 |
|
World of If | Merit Books | Novel | |
| 1960 |
|
Welten der Wahrscheinlichkeit | Widukind / Gebrüder Zimmermann | Novel | |
| August 2004 | World of If | Renaissance E Books | Novel | ||
| January 2012 |
|
World of If / Slave Raiders from Mercury | Armchair Fiction | Omnibus | |1 |