Letter (Astounding, February 1939): Concerning "Gravity Plates."
| First published | February 1939 |
|---|---|
| Type | Essay |
| Series | Letters: Willy Ley |
| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| February 1939 |
|
Astounding Science-Fiction, February 1939 | Street & Smith Publications, Inc. | MAGAZINE | 152 |