The Hollow earth theory and the evidence which disproves it.
| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| August 1986 |
|
Isaac Asimov's Science Fiction Magazine, August 1986 | Davis Publications | MAGAZINE | 4 |
| 1992 |
|
On the Past, Present & Future - 66 Essays | Barnes & Noble Books | Nonfiction | 31 |