| title | ISBN-13 | year of publication |
|---|---|---|
| The Celtic Encyclopedia: 002 | 978-1-58112-891-8 | 1998 |
| The Celtic Encyclopedia, 5 Volume Set | 978-1-58112-889-5 | 1998 |
| The Celtic Encyclopedia, Vol. 3 | 978-1-58112-892-5 | 1998 |
| The Celtic Encyclopedia, Vol. 4 | 978-1-58112-893-2 | 1998 |
| The Celtic Encyclopedia, Vol. 5 | 978-1-58112-894-9 | 1998 |