| title | media type | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|---|
| The First Signs: Unlocking the Mysteries of the World's Oldest Symbols | Paperback | 978-1-4767-8550-9 (1-4767-8550-3) | 2017 |
| The First Signs: Unlocking the Mysteries of the World's Oldest Symbols | Hardcover | 978-1-4767-8549-3 (1-4767-8549-X) | 2016 |