Millar, Adam H. “Notice of an Incised Sepulchral Slab Found in the Church of Longforgan, Perthshire”. Proceedings of the Society of Antiquaries of Scotland 34 (November 30, 1900): 463–475. Accessed April 26, 2024. https://journals.socantscot.org/index.php/psas/article/view/6787.