PETRIE, George. Description of Antiquities in Orkney recently examined, with Illustrative Drawings. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 2, p. 56–64, 1856. DOI: 10.9750/PSAS.002.56.64. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/4391. Acesso em: 20 apr. 2024.