CHRISTISON, David. The Prehistoric Forts of Peeblesshire. With Plans and Sketches. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 21, p. 13–82, 1887. DOI: 10.9750/PSAS.021.13.82. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/6225. Acesso em: 16 apr. 2024.