| title | media type | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|---|
| Collins New Naturalist Library - Northumberland | Paperback | 978-0-00-718483-5 (0-00-718483-2) | 2004 |
| Collins New Naturalist Library - Northumberland | Hardcover | 978-0-00-718484-2 (0-00-718484-0) | 2004 |
| Northumberland | " | 978-0-00-730870-5 (0-00-730870-1) | 2009 |