Skene, James. “Some Account of a Subterraneous Structure in Swabia, Supposed to Have Been Connected With the Ancient Jurisdiction of the Secret Tribunal in That Counry”. Archaeologia Scotica 3 (November 30, 1832): 17–39. Accessed April 26, 2024. https://journals.socantscot.org/index.php/arch-scot/article/view/199.