REID, Thomas. The Seven Seals of Lanark. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 53, p. 153–159, 1919. DOI: 10.9750/PSAS.053.153.159. Disponível em: //journals.socantscot.org/index.php/psas/article/view/7466. Acesso em: 19 mar. 2025.