Petrie G. Notice of the Brochs or Large Round Towers of Orkney, with Plans, Sections, and Drawings, and Tables of Measurements of Orkney and Shetland Brochs. arch-scot [Internet]. 30Nov.1891 [cited 4Jun.2023];5:71-4. Available from: http://journals.socantscot.org/index.php/arch-scot/article/view/313