“Results of Excavations at the Broch of Burrian, North Ronaldsay, Orkney, during the Summers of 1870 and 1871”, arch-scot, vol. 5, pp. 341–364, Nov. 1891, Accessed: Dec. 09, 2025. [Online]. Available: https://journals.socantscot.org/index.php/arch-scot/article/view/325