MACGREGOR, Arthur. The Broch of Burrian, North Ronaldsay, Orkney. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 105, p. 63–118, 1975. DOI: 10.9750/PSAS.105.63.118. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/8874. Acesso em: 26 apr. 2024.