TRAILL, William. Results of Excavations at the Broch of Burrian, North Ronaldsay, Orkney, during the Summers of 1870 and 1871. Archaeologia Scotica, [S. l.], v. 5, p. 341–364, 1891. Disponível em: https://journals.socantscot.org/index.php/arch-scot/article/view/325. Acesso em: 26 apr. 2024.