SIMPSON, W Douglas. Notes on Lulach’s Stone, Kildrummy, Aberdeenshire; a Symbol Stone recently found in Mortlach Churchyard, Banffshire; and other Antiquities. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 60, p. 273–280, 1926. DOI: 10.9750/PSAS.060.273.280. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/7676. Acesso em: 1 may. 2024.