Kristoffer has an impressive catalogue of books on Amazon. His latest title is "Cerridwen: Celtic Goddess of Inspiration", shown here. I can recommend all his work. As his presentation will show, he has deep knowledge of Welsh history, mythology, and the bardic tradition.
Anthony Murphy has also published a number of books on ancient Irish myth and history, also available on Amazon. One of his latest books is "Mythical Ireland: New Light on the Ancient Past", shown here. I have followed some of his delightful podcasts on Facebook, and look forward to his presentation.
I would encourage all of our prospective attendees, virtual or physical, to look over these and other publications by our authors before the retreat, as their presentations will hopefully be followed for a little time for questions!