RITCHIE, J N Graham. Two new Pictish symbol stones from Orkney. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 101, p. 130–133, 1971. DOI: 10.9750/PSAS.101.130.133. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/8745. Acesso em: 23 apr. 2024.