Available on page 76, <a target="_blank" rel="noopener" href="http://www.isfdb.org/cgi-bin/pl.cgi?GRSBCKYR1999">Bleiler (Gernsback)</a>.
Wonder Stories, March-May 1935, illustrated by Frank R. Paul.
| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| March 1935 |
|
Wonder Stories, March 1935 | Continental Publications | MAGAZINE | 1160 |
| April 1935 |
|
Wonder Stories, April 1935 | Continental Publications | MAGAZINE | 1336 |
| May 1935 |
|
Wonder Stories, May 1935 | Continental Publications | MAGAZINE | 1474 |
| 1950 | Fantastic Story Quarterly, Fall 1950 | Better Publications of Canada | MAGAZINE | 11 | |
| October 1950 |
|
Fantastic Story Quarterly, Fall 1950 | Best Books, Inc. | MAGAZINE | 11 |
| 1957 |
|
Hidden World | Avalon Books | Novel | |
| June 1964 |
|
Hidden World | Airmont Books | Novel | 5 |
| December 1972 |
|
Hidden World | Airmont Books | Novel | 5 |
| May 1973 |
|
Hidden World | Airmont Books | Novel | 5 |
| October 1975 | In Caverns Below | Garland Publishing | Novel | ||
| January 1976 |
|
Hidden World | Airmont Books | Novel | 5 |
| February 2006 | The Hidden World | Spellcaster E Books | Novel | ||
| October 2009 |
|
In Caverns Below | Thrilling Wonder | Novel | |
| May 2015 |
|
In Caverns Below / Dynasty of the Lost | Armchair Fiction | Omnibus | 5 |
| November 2021 | In Caverns Below | Project Gutenberg | Novel |