1. Anonymous. “The Original Brownies – Our Old School Friends, the Picts: Building a Broch in a Single Night” Illustrated London News 30 December 1922, 1078–1079.
2. Enlightened Zeal
3. Brand, John. A Brief Description of Orkney: Zetland, Pightland-Firth & Caithness, Wherein, after a Short Journal of the Author's Voyage Thither, These Northern Places are First more Generally Described; Then a Particular View is given of the Several Isles thereto Belonging; Together with an Account of what is most Rare and Remarkable therein: with the Author's Observes Thereupon. Edinburgh: printed by George Mosman, An. Dom, 1701. Accessed 31 August 2018. https://quod.lib.umich.edu/e/ecco/004896239.0001.000?view=toc.