KENNEDY, William Norman. Remarks on the Ancient Barrier called ’The Catrail;’ with Plans. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 3, p. 117–123, 1862. DOI: 10.9750/PSAS.003.117.121. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/4502. Acesso em: 4 may. 2024.