| title | media type | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|---|
| Drilling for Placer Gold | Hardcover | 978-0-666-55853-4 (0-666-55853-1) | 2018 |
| Drilling for Placer Gold | Paperback | 978-1-332-23673-2 (1-332-23673-1) | 2018 |
H.G. · H. Gardner · W G · W. Gardner · W H · W. H. Gardner · Walter H.