Allen, J.R. 1891. Report on the Sculptured Stones older than A.D. 1100, with Symbols and Celtic Ornament, in the District of Scotland, North of the River Dee; obtained under the Victoria Jubilee Gift of His Excellency Dr. R. H. Gunning, F.S.A. Scot. Proceedings of the Society of Antiquaries of Scotland. 25, (Nov. 1891), 422–431. DOI:https://doi.org/10.9750/PSAS.025.422.431.