Christison, David. “Forts on Whitcastle Hill, Upper Teviotdale; And Earthwork on Flanders Moss, Menteith”. Proceedings of the Society of Antiquaries of Scotland 40 (November 30, 1906): 15–22. Accessed April 28, 2024. https://journals.socantscot.org/index.php/psas/article/view/7045.