SHARPLES, Niall M et al. Excavations at Pierowall Quarry, Westray, Orkney. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 114, p. 75–125, 1985. DOI: 10.9750/PSAS.114.75.125. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/9155. Acesso em: 25 apr. 2024.