| Date | Publication | Publisher | Type | Page | |
|---|---|---|---|---|---|
| 1976 |
|
The Last Celt: A Bio-Bibliography of Robert Ervin Howard | Donald M. Grant | Nonfiction | 9 |
| November 1977 |
|
The Last Celt: A Bio-Bibliography of Robert Ervin Howard | Berkley Windhover | Nonfiction | 9 |