Gordon, George, and Arthur Mitchell. “Notice of Incised Sculpturings on the Steatite Rock at Feideland, the Extreme North of the Mainland of Shetland, and of a Cluster of Ruined Structures Styled Picts’ Houses, on the Kaim of Isbister, Shetland”. Proceedings of the Society of Antiquaries of Scotland 12 (November 30, 1877): 202–206. Accessed November 22, 2024. https://journals.socantscot.org/index.php/psas/article/view/5810.