J. M. Joass, “Notice of the Excavation of the Pictish Towers at Cinntrolla, Carnliath, and Craig-Carril in Sutherland, with Notes on Neighbouring Brochs; and an appended Report by T. Aitken, M.D., F.A.S.L., Inverness, on the Crania found in and about them”, PSAS, vol. 9, p. 60, Nov. 1872.