Joass, J Maxwell, and T Aitken. “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 (November 30, 1891): 95-130. Accessed September 24, 2020. http://journals.socantscot.org/index.php/arch-scot/article/view/314.