Allen, John Romilly. “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”. Proceedings of the Society of Antiquaries of Scotland 31 (November 30, 1897): 147–152. Accessed May 2, 2024. https://journals.socantscot.org/index.php/psas/article/view/6658.