“Notice of a Sculptured Stone With Ogham Inscription, from Latheron, Presented to the National Museum by Sir Francis Tress Barry, Bart., M.P. Hon. F.S.A. Scot., Keiss Castle, Caithness; And of Two Sculptured Stones, Recently Discovered by Rev. D. Macrae, B.D., at Edderton, Ross-Shire”. 1904. Proceedings of the Society of Antiquaries of Scotland 38 (November): 534-41. https://doi.org/10.9750/PSAS.038.534.541.