ELLIS, John. J N Graham Ritchie. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 135, p. 1–4, 2006. DOI: 10.9750/PSAS.135.1.4. Disponível em: //journals.socantscot.org/index.php/psas/article/view/9666. Acesso em: 30 mar. 2025.