- The Barddas of Iolo Morganwg: A Collection of Original Documents, Illustrative of the Theology Wisdom, and Usages of the Bardo-Druidic Systems of the Isle of Britain
- Annales Cambriae (444 - 1288)
- Barddas: Or, a Collection of Original Documents, Illustrative of the Theology, Wisdom, and Usages of the Bardo-Druidic System of the Isle of Britain, Volume 2
- Gweithian Ioan Mai
- An Enquiry into the Truth of the Tradition, Concerning the Discovery of America, by Prince Madog ab Owen Gwynedd, about the Year, 1170