Joass, J. M., & Aitken, T. (1891). The Brochs or Pictish Towers of Cinn-Trolla, Carn-Liath, and Craig-Carril, in Sutherland, with Notes on other Northern Brochs. With Report upon the Crania found in and about them. Archaeologia Scotica, 5, 95–130. Retrieved from https://journals.socantscot.org/index.php/arch-scot/article/view/314