Report on the Photography of the Sculptured Stones Earlier Than A.D. 1100, in the District of Scotland South of the River Dee; Obtained under the Jubilee Gift of His Excellency Dr. R. H. Gunning, LL.D., F.S.A. Scot. PSAS 1897, 31, 147-152. https://doi.org/10.9750/PSAS.031.147.152.