ACLAND, C L. Notes on the Broch of Copister in Yell Sound, Shetland. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 24, p. 473–474, 1890. DOI: 10.9750/PSAS.024.473.474. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/6374. Acesso em: 4 may. 2024.