Petrie G. Notice of the Brochs or Round Towers of Orkney, with Plans, Sections, and Drawings, and Tables of Measurements of Orkney and Shetland Brochs. PSAS [Internet]. 1872 Nov. 30 [cited 2024 Nov. 22];9:60. Available from: https://journals.socantscot.org/index.php/psas/article/view/5497