Matheson, James, and Cosmo Innes. “Notice of a Chamber Recently Excavated in the Stone Circle of Callernish in the Lewis”. Proceedings of the Society of Antiquaries of Scotland 3 (November 30, 1862): 110-112. Accessed December 3, 2023. http://journals.socantscot.org/index.php/psas/article/view/4499.