TRAILL, William. Results of Excavations at the Broch of Burrian, North Ronaldshay, during the Summers of 1870 and 1871. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 9, p. 547, 1873. DOI: 10.9750/PSAS.009.547.2. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/5540. Acesso em: 6 may. 2024.