CLOUSTON, J Storer. An Early Orkney Castle. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 60, p. 281–300, 1926. DOI: 10.9750/PSAS.060.281.300. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/7677. Acesso em: 5 may. 2024.