| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| Celtic Myth and Religion: A Study of Traditional Belief, with Newly Translated Prayers, Poems and Songs | 978-0-7864-6476-0 (0-7864-6476-3) | 2011 |
| The Divine Feminine in Ancient Europe | 978-0-7864-7138-6 (0-7864-7138-7) | 2013 |