DUNS, Professor. On some Rock-Markings. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 20, p. 126–136, 1886. DOI: 10.9750/PSAS.020.126.136. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/6187. Acesso em: 4 may. 2024.