Coles, Frederick R. “Notice of Standing Stones, Cists, and Hitherto Unrecorded Cup-and-Ring-Marks in Various Localities”. Proceedings of the Society of Antiquaries of Scotland 40 (November 30, 1906): 291–327. Accessed May 7, 2024. https://journals.socantscot.org/index.php/psas/article/view/7062.