Letter (Astounding, December 1939): I know There Are Formulas, But I've Forgotten 'em
| First published | December 1939 |
|---|---|
| Type | Essay |
| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| December 1939 |
|
Astounding Science Fiction, December 1939 | Street & Smith Publications, Inc. | MAGAZINE | 106|106.2 |