CHRISTISON, David. The Forts of Selkirk, the Gala Water, the Southern Slopes of the Lammermoors, and the North of Roxburgh. Proceedings of the Society of Antiquaries of Scotland, [S. l.], v. 29, p. 108–179, 1895. DOI: 10.9750/PSAS.029.108.179. Disponível em: https://journals.socantscot.org/index.php/psas/article/view/6583. Acesso em: 7 may. 2024.