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 29 (November 30, 1895): 108–179. Accessed May 7, 2024. https://journals.socantscot.org/index.php/psas/article/view/6583.