BRUCE, John; NELSON, E M. Notice of the Excavation of a Broch at Jarlshof, Sumburgh, Shetland. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 41, p. 11–33, 1907. DOI: 10.9750/PSAS.041.11.33. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/7075. Acesso em: 4 may. 2024.