Allen, John Romilly. “Preliminary List of Sculptured Stones Older Than A.D. 1100, With Symbols and Celtic Ornament, in Scotland”. Proceedings of the Society of Antiquaries of Scotland 24 (November 30, 1890): 510–525. Accessed November 22, 2024. https://journals.socantscot.org/index.php/psas/article/view/6377.